Are Animals For Biomedical Research Bred For Genetic Uniformity
Ups J Med Sci. March, 2016; 121(1): 1–eleven.
Domestic animals as models for biomedical research
Leif Andersson
1Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
2Department of Animal Convenance and Genetics, Swedish Academy of Agricultural Sciences, Uppsala, Sweden
3Section of Veterinary Integrative Biosciences, Texas A&M University, College Station, USA
Received Received on August 31, 2015; Revised Revised on September 02, 2015; Accepted Accepted on September 03, 2015.
Abstract
Domestic animals are unique models for biomedical research due to their long history (thousands of years) of potent phenotypic selection. This procedure has enriched for novel mutations that have contributed to phenotype evolution in domestic animals. The characterization of such mutations provides insights in gene function and biological mechanisms. This review summarizes genetic dissection of about 50 genetic variants affecting pigmentation, behaviour, metabolic regulation, and the pattern of locomotion. The variants are controlled by mutations in about 30 unlike genes, and for 10 of these our group was the beginning to report an clan betwixt the gene and a phenotype. Most half of the reported mutations occur in non-coding sequences, suggesting that this is the well-nigh common blazon of polymorphism underlying phenotypic variation since this is a biased list where the proportion of coding mutations are inflated as they are easier to find. The review documents that structural changes (duplications, deletions, and inversions) have contributed significantly to the evolution of phenotypic variety in domestic animals. Finally, we depict five examples of evolution of alleles, which ways that alleles have evolved by the accumulation of several consecutive mutations affecting the function of the same factor.
Keywords: Comparative genomics, domestic animals, mutation detection
Winner of the Rudbeck Award 2013, at the Medical Kinesthesia of Uppsala Academy for his pioneering studies of the pathogenesis of many non-catching diseases by means of molecular and animal genetics.
Introduction
During the last 30 years I have used domestic animals as models for biomedical research. Why domestic animals, when there are well-established brute models such as mouse, zebra fish, and Drosophila? The unique feature of domestic animals is their long history of selective breeding. Ever since the first animals were domesticated (ane) humans accept changed their gene pools by favouring animals that could survive and reproduce in captivity, and that provided useful commodities to humans such as nutrient, pare and fur, transportation, and company. Domestication and breeding is an evolutionary process in which gene variants with favourable phenotypic furnishings are enriched. A major aim in animal genomics as well every bit in nigh genome projects is to reveal genotype–phenotype relationships and to study their underlying molecular mechanisms.
In my PhD thesis defended in Dec 1983 I expressed the vision that the emerging methods of molecular genetics volition unleash the full potential of domestic animals equally models for genetic studies of phenotypic traits. I started this research programme the following twelvemonth as a guest postal service-doctoral fellow at the Department of Cell Enquiry in Uppsala led past Per A. Peterson and Lars Rask—two of the pioneers applying molecular genetics for biomedical research in Sweden. Furthermore, they led a strong research programme on major histocompatibility circuitous (MHC) genes and their role in the human immune system. This area was and all the same is of considerable involvement in domestic animals considering immune response and disease resistance are of major importance in animal breeding. Thus, during my first years equally an independent researcher I characterized the MHC class II region in cattle and demonstrated the presence of extensive genetic variety at this locus (2), as well as providing evidence that genetic polymorphism at the cattle DRB3 locus is maintained by balancing selection (3). Notwithstanding, past the end of the 1980s, afterward PCR was invented, it became possible to do genome inquiry, and since then my research squad has been working in the field of genetics and genomics. Table I provides a comprehensive listing of phenotypic traits in various domestic animals where we have identified the underlying gene and in near cases the specific mutation(south) causing a phenotypic effect.
Tabular array I.
Genes and mutations associated with phenotypic traits in domestic animals.
| Phenotype | Gene | Mutation identified | Type of mutationa | Ref. |
|---|---|---|---|---|
| Horse | ||||
| Anecdote coat colour | MC1R | Aye | Missense | (48) |
| Roan coat color | KIT | No | Non-coding | (49) |
| Argent coat color | PMEL | Yes | Missense | (fifty) |
| Greying with age | STX17 | Yes | four.6 kb duplication | (51) |
| Gait | DMRT3 | Yep | Nonsense | (44) |
| Pig | ||||
| Dominant white colour | KIT | Yes | Duplication +splice mutation | (thirteen,52–55) |
| Patch coat color | KIT | Yes | Duplication | (13,52,54,55) |
| Chugalug coat color | KIT | Yes | Duplication(s) | (55,56) |
| Dominant black color | MC1R | Yep | Missense | (57) |
| Recessive red colour | MC1R | Aye | Missense | (57) |
| Black spotting | MC1R | Yes | 2 bp insertion + missense | (15) |
| Black-and-tan coat colour | ASIP | No | Not-coding | (58) |
| Hypercholesterolemia | LDLR | Yes | Missense | (5) |
| Muscle glycogen content | PRKAG3 | Aye | Missense | (27) |
| Muscle growth | IGF2 | Yes | SNP | (37) |
| Chicken | ||||
| Dominant black color | MC1R | Yes | Missense | (59) |
| Buttercup colour | MC1R | Yes | Missense | (59) |
| Dominant white color and feather pecking | PMEL | Yeah | ix bp insertion | (16,sixty) |
| Dun color | PMEL | Yes | fifteen bp deletion | (16) |
| Smoky color | PMEL | Yeah | ix bp insertion + 12 bp deletion | (16) |
| Silver | SLC45A2 | Yes | Missense | (61) |
| Sexual practice-linked imperfect albinism | SLC45A2 | Yes | i bp insertion | (61) |
| Sex-linked barring | CDKN2A/B | Yes | Non-coding + missense | (62) |
| Night chocolate-brown color | SOX10 | Yes | 8.3 kb deletion | (12) |
| Yellow skin | BCDO2 | No | Non-coding | (63) |
| Fibromelanosis | EDN3 | Yes | Duplications | (64) |
| Silky feather | PDSS2 | Yes | SNP | (65) |
| Pea-comb | SOX5 | Yes | CNV | (66) |
| Rose-rummage | MNR2 | Yes | 7.4 Mb inversion | (4) |
| Sperm motility | CCDC108 | Yes | 7.4 Mb inversion | (4) |
| Duplex comb | EOMES | Aye | xx kb duplication | (67) |
| Crested | HOXC8 | No | Non-coding | (68) |
| Growth | SH3RF2 | Yeah | Deletion | (fourteen) |
| Dog | ||||
| Leukocyte adhesion deficiency | ITGB2 | Yes | Missense | (half dozen) |
| White spotting (Due south)b | MITF | Yes | Non-coding | (vii,69) |
| Dorsal hair ridge | Multiple | Yeah | 133 kb duplication | (70) |
| Sensory ataxic neuropathy | mt_tRNATyr | Yes | ane bp deletion | (71) |
| Shar-pei fever | HAS2 | Yeah | Duplication | (72) |
| Cattle | ||||
| Fishy off-flavour | FMO3 | Yes | Nonsense | (eight) |
| Dominant crimson color | COPA | Yep | Missense | (73) |
| Water buffalo | ||||
| White spotting | MITF | Yes | Nonsense | (74) |
| White spotting | MITF | Yes | Splice site | (74) |
| Japanese quail | ||||
| Cinnamon colour | SLC45A2 | Yeah | Missense | (61) |
| Sex-linked imperfect albinism | SLC45A2 | Yes | Splice site | (61) |
My vision to use domestic animals as models for biomedical research by taking advantage of the advances in molecular genetics and genomics has been shown to be a fruitful approach that has resulted both in new bones knowledge and in practical applications. However, during the first twenty years of my career it was not easy to convince funding bodies that this was an approach worth supporting. My research applications were sometimes rejected by funding bodies supporting agricultural research because the approach was considered of express practical interest and was rather to exist classified as basic enquiry, and the applications were consistently rejected by the Swedish Research Quango (supporting basic research) because they were considered too applied.
Enquiry on the genetic basis for diseases and disorders in domestic animals is of outmost importance for veterinary medicine and fauna breeding in order to keep disease incidence at a minimum level. However, domestic animals are less important equally models for human affliction for several reasons. Firstly, genetic variants causing disease usually occur at a low frequency because there is strong selection to eliminate unfit animals, in particular in the animals we utilize for food production. Secondly, the clinical characterization of disease is rarely every bit advanced in animals as in human medicine. Thirdly, thank you to the evolution of powerful methods for genetic studies in humans the need for using animals to identify candidate genes for human disease has become less important. Yet, when one finds mutations in domestic animals in genes associated with human illness, the domestic brute can be used as a model to develop disease prevention and new treatments.
The major merit of domestic animals as models for biomedical research relates to the rapid phenotypic evolution that has occurred during the class of animal domestication. Here domestic animals give a unique possibility to gain insight into molecular mechanisms underlying phenotypic alter. The aim with this review is to give examples of of import discoveries that we have made by studying some of the traits under selection in domestic animals.
General lessons
Table I lists 50 phenotypes in various domestic animals for which my group has been involved in a study that has resulted in the detection of the underlying gene and in most cases the underlying mutation(s). This list involves about thirty unlike genes. The number of genes is lower than the number of traits considering some genes are associated with multiple phenotypes. For example, we have identified mutations in the melanocortin 1 receptor (MC1R) gene underlying six different variant alleles affecting pigmentation in horse, pig, and chicken. For nearly x of the genes listed in Table I our study was the first in whatever organism that has documented an clan between that gene and a phenotype. These studies have therefore contributed to the functional annotation of the vertebrate genome. For example, the paper on our finding that a 7.four Mb inversion disrupts the coiled-coil domain containing 108 gene (CCDC108) which leads to poor sperm motility in homozygous Rose-comb roosters (4) is still the just publication on the CCDC108 gene in any organism. Information technology is likely that loss-of-function mutations affecting this sperm protein gene are also causing reduced sperm motion and reduced fertility in some man males.
Only a handful of the traits listed in Table I are obvious disorders. Ane example is a missense mutation in the low-density lipoprotein receptor cistron (LDLR) that we identified in a strain of pigs used as models for hypercholesterolemia in humans (5). Other examples include leukocyte adhesion deficiency in dogs caused past a missense mutation in the integrin beta 2 (ITGB2) gene (6), sensory ataxic neuropathy in dogs acquired by a one base pair deletion in the mitochondrial genome (vii), and fishy off-flavor in cattle, a status where homozygous cows produce milk that smells of rotten fish, caused past a missense mutation in the flavin containing monooxygenase three (FMO3) gene (8). Mutations in the respective genes cause very similar diseases or disorders in humans. In the three final-mentioned cases a diagnostic Deoxyribonucleic acid test has been developed and used to reduce or eliminate disease. Furthermore, a colony of Irish setters carrying the mutation causing leukocyte adhesion deficiency was later on used as a model for human being gene therapy (9). Ill dogs were cured by introducing a functional copy of the ITGB2 gene ex vivo into hematopoietic stalk cells which were then introduced to the afflicted animal, an example of how a big animal model could be very valuable for the evolution of new therapeutic strategies in human medicine.
A long-standing question in biological science is the relative importance of coding and non-coding mutations for explaining phenotypic variation and disease (10). Almost 50% of the mutations listed in Table I are non-coding, and this strongly suggests that non-coding mutations by far dominate among the mutations underlying the phenotypic diversity present in domestic animals. This conclusion is based on the fact that this is a biased estimate inflating the proportion of coding changes because they are much easier to find. Firstly, changes in coding sequences often pb to alleles with more striking phenotypic effects. Secondly, it is much more than straightforward to interpret the functional consequence of changes in coding sequence than in non-coding sequence. These conclusions are consistent with data from human genetics showing that whereas a majority of mutations causing severe inherited disorders affects coding sequences, a majority of sequence variants associated with increased risk for a multifactorial disorder occurs in non-coding sequences (11).
Our characterization of the genetic ground for a phenotypic trait has revealed the importance of structural changes (deletions, duplications, and inversion). Tabular array I lists almost ten examples of structural changes being the causal mutation for a phenotypic trait. A mutual theme hither is that the structural modify leads to contradistinct regulation of i or several of the genes straight afflicted past the structural modify or located in the close vicinity of the structural change. This may occur considering a regulatory element is deleted (e.g. Night brown color in craven) (12), or duplicated (e.1000. Greying with age in horses) (13), or because a gene has been translocated to some other position and is there influenced by another constellation of regulatory elements (e.thou. Rose-comb in craven) (iv).
Some other interesting finding is that we take documented evolution of alleles, which means the accumulation of multiple consecutive causal mutations in the same gene. The genetic literature on the identification of causal mutations is largely based on studies of monogenic disorders in humans or mutations causing monogenic phenotypes in experimental organisms. These are almost always due to a single hit. However, our information from domestic animals gives a unlike picture considering animal domestication has a sufficiently long history (nearly 10,000 years) to allow development of alleles. We have so far documented v examples where multiple causal mutations contribute to a phenotype: Dominant white colour in pigs (14), Blackness spotting in pigs (xv), Smoky colour in chicken (16), the Rose-comb2 allele in chicken (4), and White-spotting in dogs (7). Information technology appears plausible that a considerable portion of the phenotypic diversity that occurs in natural populations, including the one underlying the chance to develop multifactorial disorders in humans, is due to allelic variants that differ past multiple causal differences rather than single mutations with large effects.
Pigment prison cell biological science
Many of the phenotypes listed in Tabular array I are related to pigmentation. Pigmentation has been used throughout the history of genetics as a model to study how genes human action and interact considering they oft show a simple monogenic inheritance that likewise facilitates the identification of coincidental genes and mutations. Furthermore, the phenotypic readout is precise, allowing the scoring of subtle phenotypic differences.
A striking divergence between domestic animals and their wild ancestors is the amazing coat colour variety, as species in the wild in most cases show very modest variation. In fact, coat color was one of the first traits that changed later on domestication, and color variants in domestic animals are mentioned in some of our earliest written records from the Ur III dynasty in Mesopotamia dated to near 5,000 years before present (17). So why did the coat color change in our domestic animals? Most importantly, humans take actively selected for colour variation among domestic animals because 1) this immune us to distinguish our prized domesticated animals from their wild ancestors at a time when factor flow oftentimes occurred; 2) selection confronting camouflage facilitated animal husbandry; and 3) we and apparently our ancestors appreciate multifariousness of colour and therefore have kept animals carrying novel phenotypes as long as the variant is not associated with deleterious effects that reduce their utility. Relaxed purifying pick has most likely also contributed to the rich glaze color multifariousness in domestic animals.
Our report comparing genetic variation in the melanocortin 1 receptor (MC1R) gene among wild and domestic pigs illustrates the striking difference in pick pressure in the wild and at the farm (18). MC1R is expressed at the jail cell surface of melanocytes and has a critical part in determining pigmentation in vertebrates because it controls paint switching, with the absence or presence of MC1R signalling beingness associated with the synthesis of red and black pigment, respectively (19). Mutations in MC1R are clearly the well-nigh common reason for different colour morphs both in domestic animals and in wild species, most likely because the function of MC1R is largely restricted to the pigment prison cell, which ways that mutations in this gene are not associated with strong negative effects on other traits. MC1R mutations are causing the ascendant black, recessive cerise, and black spotting coat colour variants in pigs (Table I). A hit difference between wild boars and domestic pigs is that the wild boar piglets are striped whereas piglets conveying MC1R mutations are non (Figure 1). The striping pattern is a cover-up colour requiring MC1R paint switching, and this mechanism is disrupted by these mutations (18). In our study we sequenced the entire MC1R coding sequence from European and Chinese domestic pigs as well as European and Asian wild boars. We identified seven dissimilar sequence variants among the wild boars, and all were synonymous, and thus all tested wild boars expressed an identical MC1R protein sequence despite the fact that European and Asian wild boars are classified as different subspecies that diverged about 1 meg years ago (20). This indicates stiff purifying selection to maintain camouflage color in the wild. In contrast, nine out of ten sequence variants detected among domestic pigs inverse the protein sequence consistent with strong selection to alter colour. In this study we analysed 51 different grunter breeds from Europe and China, and almost all breeds carried MC1R mutations. The but exception was the Mangalica pig from Hungary that carried the MC1R wild-type allele, and their piglets are in fact striped like the wild boar!
Winner of the Rudbeck Honor 2013, at the Medical Kinesthesia of Uppsala University for his pioneering studies of the pathogenesis of many non-infectious disease by means of molecular and brute genetics.
The blackness spotting phenotype in pigs (Figure 1B) is a particularly interesting variant because this allele is the result of ii consecutive mutations (15). Firstly, it carries the D121N missense mutation leading to a constitutively active receptor causing the ascendant blackness color variant. In addition, the blackness spotting allele is associated with a ii base of operations pair insertion at codon 23 (nt67insCC) causing a frameshift and thus a complete loss-of-function. As explained above, lack of MC1R signalling is expected to lead to only carmine/yellow pigmentation, so how can these pigs show blackness spots? Past sequencing MC1R mRNA isolated from black spots we were able to demonstrate that this is acquired by somatic mutations that restore the reading frame. The most probable caption why this happens at a high frequency is that the insertion of two cytosine nucleotides occurs in a stretch of six cytosines and this results in a mononucleotide repeat (CCCCCCCC) that is somatically unstable. This illustrates why studies on pigmentation have been and so rewarding because it would have been extremely challenging to reveal such a somatically unstable mutation if the factor for instance afflicted insulin secretion unless i characterized the release from individual cells. The MC1R blackness spotting allele is one of our examples of 'evolution of alleles' by the aggregating of several consecutive mutations affecting the same gene.
Behaviour
Behaviour is another trait that has changed dramatically after animal domestication. Changes in behaviour were required for the animals to survive and reproduce in captivity. There is a huge potential to study the genetic basis for variation in behaviour in dogs due to the complex interaction between humans and dogs that has evolved since domestication (21). There is also a very fascinating diversity in behaviour among breeds where dogs accept been bred for diverse tasks such as herding, hunting, retrieving diverse objects, guarding, or simply for pleasure as a companion to humans. However, then far, little progress has been fabricated in identifying specific genes underlying variation in dog behaviour. A possible reason is that behaviour has a very complex genetic background with many genes involved.
We accept used the rabbit as a model to study the genetic basis for domestication (22). There are 3 main reasons why the rabbit is a good model for studies of domestication. Firstly, domestication is relatively recent, just about 1,400 years agone. Secondly, we know where rabbit domestication took place (Southern French republic), and at that time wild rabbits (Oryctolagus cuniculus) were restricted to Southern France and the Iberian Peninsula. Thirdly, the area where domestication happened is still densely populated with wild rabbits that tin be sampled for genetic studies. Thus, we tin can brand very precise comparisons of allele frequency differences betwixt domestic rabbits and relevant populations of wild rabbits. This is more than hard for other domestic animals. For instance, domestication of the wolf happened a long time ago (fifteen,000 years before nowadays or earlier) (one), and at that time wolves were spread across the entire Northern hemisphere. Information technology is also possible that the population(s) of wolves that contributed mostly to dog domestication has become extinct due to human expansion. Furthermore, since domestication there has probably been a considerable amount of gene flow between wolves and dogs. This complex demographic history blurs the picture because it is difficult to deduce whether an observed deviation in allele frequency between dogs and gimmicky wolves is caused past option, genetic migrate, or because at that place is a genetic difference betwixt contemporary wolves and the wolf population(s) that contributed to dog domestication.
We carried out whole-genome sequencing of 14 population samples of wild rabbits and 6 breeds of domestic rabbits (22). We sequenced pools of animals from each population, and each pool comprised 10 to xx animals. The rabbit is one of the most polymorphic mammals sequenced so far, and the nucleotide multifariousness measured as the average number of nucleotide substitutions per ane,000 base pairs betwixt two random chromosomes is nine times higher in rabbits (about 9) than in humans (nigh one). Nosotros identified a full of fifty million SNPs in rabbits and compared the allele frequency of these in wild and domestic rabbits. This analysis revealed potent signatures of choice and the major conclusions were: 1) rabbit domestication has a highly polygenic basis involving many hundreds of genes; ii) non-coding changes dominate largely over changes in coding sequence; iii) we observed very few consummate fixations but rather shifts in allele frequencies consistent with a polygenic basis where the majority of loci take pocket-sized phenotypic effects; and iv) sequence variants in the vicinity of genes with an established part in brain and neuronal evolution were highly enriched among those showing the strongest differentiation betwixt wild and domestic rabbits. This implies that changes in genes affecting behaviour have played a prominent part during rabbit domestication. This result makes perfect sense because the wild rabbit has a very stiff flight response making it extremely difficult to go on them in captivity, whereas domestic rabbits are well adapted to a life in captivity. In fact, Charles Darwin wrote in On the Origin of Species that '… hardly any animal is more than difficult to tame than the young of the wild rabbit; scarcely any fauna is tamer than the young of the tame rabbit …' (23). We postulated that tame behaviour in rabbits and other domestic animals has a truly complex genetic background and evolved by shifts in allele frequencies at many loci rather than by critical changes at a few domestication loci.
Metabolic traits
The metabolism of our domestic animals has often been drastically altered by our demand to use them for nutrient production. A good example is layer chicken that accept been selected to produce more than 300 eggs during a yr without being mated to a rooster, whereas its wild ancestor, the red junglefowl female person, normally produces one clutch of eggs after mating. Nosotros have in particular studied the altered metabolism and body composition in pigs. Since the 1940s there has been a drastic increase in pig muscle growth and a respective decrease in fatty deposition due to the consumer's need for lean meat. This was accomplished after procedures to measure torso composition (the relative proportion of protein and fatty in the carcass) were introduced and powerful statistical methods for calculating breeding values were adult. We have identified 2 major loci that take responded to the potent pick for lean meat: the RN locus affecting glycogen content in skeletal musculus, and the IGF2 locus affecting muscle growth.
The RN story started in France where researchers noted that at that place was a meat quality problem in Hampshire pigs since a large proportion of the individuals produced meat with an unusually low pH (measured 24 h later on slaughter), reduced water-property capacity, and reduced yield of cured cooked ham. This had a large result on hog product worldwide since it is a common practice to employ Hampshire pigs equally a sire line mated to a dam line, which means that a large proportion of the pigs used for meat production would take a Hampshire male as the father. Further research revealed that these furnishings on meat quality were due to a 70% increment in glycogen content in skeletal muscle and that this phenotype showed a elementary monogenic inheritance with two alleles, RN− (high glycogen) and rn+ (normal glycogen) (24). The fact that liver glycogen was normal in mutant pigs suggested that the mutation underlying this phenotype affected the function of a muscle-specific isoform not expressed in the liver.
In the mid-1990s we and others decided to attempt to place the gene underlying the RN phenotype by positional cloning, but this was very challenging at the time because there was no genome assembly available from any vertebrate. The first step was to map the locus to a region on squealer chromosome 15 past classical linkage analysis using pedigree data (25). We then investigated whether the respective region in the more well-studied human genome harboured any candidate genes with a known part in glycogen metabolism, but that was not the case. We then carried out a very laborious procedure where we isolated the unabridged region harbouring the RN locus in overlapping bacterial artificial chromosomes (BACs) (26). The BACs were used to isolate new genetic markers and for further fine mapping that eventually resulted in the assignment of the locus to a region of most 100 kb present in a single BAC. We sequenced this unabridged BAC and identified four genes. One of these was especially interesting because it encoded a homolog to the regulatory γ-chain of the SNF4 kinase in yeast that has a primal role in sugar metabolism including glycogen metabolism. This kinase named AMP-activated protein kinase (AMPK) in vertebrates is a heterotrimeric protein composed of a catalytic α-chain and non-catalytic β- and γ-bondage. At the time two α-chain genes (PRKAA1 and PRKAA2), two β-chain genes (PRKAB1 and PRKAB2), and two γ-chain genes (PRKAG1 and PRKAG2) had been identified in humans. We therefore named our newly discovered isoform PRKAG3 (27). The fact that AMPK is an of import energy-sensing enzyme, activated by high AMP–depression ATP, fabricated it an excellent positional candidate gene for the RN phenotype. Northern blot analysis provided very strong back up for this notion because it revealed that PRKAG3 is a musculus-specific isoform non expressed in the liver, in perfect understanding with the RN phenotype. Furthermore, sequence assay revealed an R225Q missense mutation at a site that is extremely well conserved among AMPK γ-chains in eukaryotes. Genetic analyses in many thousands of pigs have provided conclusive prove that R225Q is the causal mutation for the RN phenotype.
The twelvemonth afterward our discovery, some other group reported the identification of a quantitative trait locus (QTL) for glycogen content that mapped to the PRKAG3 region, and they could exclude the presence of the R225Q mutation (28). The data strongly suggested that the causal mutation for this phenotype (lower glycogen than the wild-type) was a missense mutation V224I at the neighbouring residue. Transfection experiments in COS cells demonstrated that the wild-type allele V224R225 showed low kinase activity at low AMP and was activated past high AMP, whereas the V224Q225 (RN- ) allele was constitutively active, and the 3rd allele I224R225 showed low activity and could non be induced by high AMP (29). Thus, the event in this analysis is a perfect match in relation to the glycogen content in skeletal muscle V224Q225 > V224R225 > I224R225. The explanation for the stiff effects of these missense mutations became apparent a few years afterward when information technology was demonstrated that these two residues are located in the binding pocket for AMP and ATP that regulates AMPK activity (xxx).
To explore farther the functional significance of the PRKAG3 isoform nosotros created transgenic mice overexpressing the wild-blazon (R225) or mutant (Q225) forms in skeletal muscle equally well as a PRKAG3 knock-out mouse (29). The transgenic mutant but not the transgenic wild-type mouse showed excess glycogen content in skeletal muscle and thus replicated the pig phenotype. Surprisingly, the knock-out mice showed normal glycogen levels and normal glycogen utilization during practise. However, re-synthesis of glycogen after exercise was impaired, and in vitro tests on skeletal musculus showed defective AMPK-mediated glucose uptake (29). Taken together the combined pig and mouse data evidence that the AMPK isoform containing the muscle-specific γ3-chain has a key office in monitoring glycogen content in white skeletal muscle and promotes glycogen re-synthesis after exercise by activating glucose uptake and fatty oxidation (29). In humans, a rare naturally occurring R225W mutation affecting the same rest as the pig R225Q mutation has been reported (31,32). Individuals carrying this mutation showed nearly 90% higher glycogen content in skeletal muscle, about 30% lower intramuscular triacylglycerol content, and no obvious impairment in glucose metabolism, in agreement with the pig and transgenic mouse phenotypes associated with the R225Q mutation.
The PRKAG3 poly peptide is a validated drug target for treatment of type II diabetes. Information technology is plausible that a drug activating the AMPK isoform involving PRKAG3 would take a positive consequence on blood glucose levels by activating insulin-independent glucose uptake and promoting fatty acid oxidation mimicking the effects of exercise. However, the project is challenging because information technology is more difficult to activate a kinase than to inactivate it; in the latter instance one 'but' needs to find a small-scale molecule that interferes with poly peptide function.
The discovery of the mutation in IGF2 encoding insulin-like growth factor Ii was fabricated using our intercross between Large White domestic pigs and the European wild boar (33). This intercross was initiated already 1989 with the appetite to develop a comprehensive linkage map for pigs and to map loci underlying phenotypic traits. The full-blooded comprised 200 Fii progeny that were advisedly phenotyped for a range of traits including torso composition and weight of internal organs. A genetic assay revealed a paternally expressed QTL with major effects on muscle growth, subcutaneous fat depth, and the size of the centre that mapped to the IGF2 region (34). F2 progeny that had inherited the domestic squealer allele showed iii%–iv% more muscle, lower subcutaneous fat depth, and had a bigger heart. The fact that both this QTL and IGF2 showed paternal expression and that IGF2 is an of import growth factor strongly suggested that the causal mutation(s) for this QTL affected IGF2 office.
Sequence analysis revealed that the IGF2 coding sequence was identical in wild boar and domestic pigs, suggesting a regulatory mutation. A problem with genetic analysis of quantitative traits or multifactorial disorders is that in that location is no simple one-to-i relationship betwixt genotype and phenotype because each QTL controls just a fraction of the variance. Still, in domestic animals information technology is possible to transform a quantitative trait to a Mendelian trait by progeny testing. In collaboration with Michel Georges (Academy of Liège, Belgium), who had independently identified the IGF2 QTL in an intercross between Large White and Piétrain pigs (35), we used full-blooded assay to identify private sires that segregated for the QTL and so sorted their chromosomes equally Q (for loftier muscle growth) and q (wild-blazon). Sequence analysis of the entire IGF2 region as well every bit the flanking regions including the insulin gene showed that the mutation(s) underlying the QTL must exist located inside the IGF2 region since all Q chromosomes were identical-past-descent (IBD) for a 29 kb region within IGF2. The problem was that the sequence divergence between the Q and q chromosomes was equally high as one%, significant that there were about 300 sequence differences betwixt the two types of chromosomes. A 1% sequence departure is uncommonly high between 2 alleles from the aforementioned species (cf. orthologous sequences from homo and chimpanzee show on boilerplate a i.two% sequence difference), and we therefore hypothesized that the Q allele may originate from Asian pigs since we had shown a few years earlier that European and Asian pigs were domesticated from different subspecies of wild boars and that there has been a considerable import of Asian pigs into Europe during the eighteenth and nineteenth centuries (36). Nosotros therefore started a collaboration with Alan Archibald and Chris Haley (The Roslin Institute, Edinburgh, UK) who had developed an intercross between Chinese Meishan pigs and European Large White pigs. Statistical and sequence analysis showed that the Meishan pigs carried chromosomes classified as q, and it turned out that these differed from the Q allele by a single base alter (C to Yard) in intron 3 of IGF2, providing conclusive genetic testify that this must be the causal mutation (37). This was the first study in whatever organism that revealed the causal mutation for a multifactorial trait or disorder as a unmarried base change in a not-coding region. This major achievement, accomplished long before there was a grunter genome assembly, is a cute analogy of how powerful genetic studies in domestic animals can be past combining all-encompassing full-blooded analysis and the rapid development that makes information technology sometimes possible to identify the wild-blazon bequeathed chromosome for a mutant chromosome. It is notwithstanding an open question whether the IGF2 mutation arose in Asian wild boars earlier domestication, in Asian domestic pigs prior to introgression to European pigs, or in Europe afterwards introgression of a wild-type Asian chromosome. This mutation has gone through a selective sweep in modern meat-producing pigs, and a very high proportion of all pigs used for meat product worldwide carry this mutation.
The IGF2 mutation occurs at an evolutionary conserved CpG island in intron three; 16 base pairs involving the mutated site bear witness 100% sequence identity among eighteen out of xviii mammalian species (38). Gel shift experiments revealed that the mutation disrupts the interaction with a nuclear gene nowadays in mouse C2C12 myoblast cells, and a Luciferase reporter assay in the same cell blazon showed that the wild-type sequence just not the mutant sequence supports repression of transcription from the endogenous IGF2 promoter (37). This result was in perfect understanding with expression analysis showing upregulated IGF2 expression in postnatal skeletal and cardiac muscle from mutant chromosomes but not in prenatal musculus or in liver. Thus, the mutation knocks out the interaction with a repressor, and the consequence of the mutation is both tissue- and stage-specific.
The remaining big question afterward the identification of the IGF2 mutation was which transcription factor binds the wild-blazon sequence. The mutation did non disrupt the recognition sequence for a known factor, suggesting that it is an unusual site for a known gene or that an uncharacterized cistron binds to the site. The latter turned out to be the right answer when we half dozen years afterward in collaboration with researchers at the Wide Institute (Cambridge, United states) were able to fish out the factor from preparations of SILAC-labelled C2C12 nuclear proteins using biotin-labelled wild-type and mutant oligonucleotides (39). The protein that we named ZBED6 was not just an uncharacterized transcription factor merely a previously unknown protein. The reason why it was non annotated every bit a protein in the man and mouse genomes was that it is encoded by a domesticated DNA transposon located in an intron of another gene, ZC3H11A. Bioinformatic analysis indicated that this Dna transposon must have integrated in the genome more than than 200 one thousand thousand years ago, before the separate between monotremes and other mammals, but the open reading frame is only maintained in placental mammals. The information imply that ZBED6 is an innovation in placental mammals that evolved after the divergence of the ancestors of marsupials and placental mammals. The extremely high sequence conservation of the two DNA-binding BED domains amongst placental mammals (39) suggests that sequence changes in these regions are not tolerated and that ZBED6 has evolved an essential function. Fleck-seq analysis revealed about 2,500 putative ZBED6 binding sites in mouse C2C12 cells, and the consensus binding motif GCTCG was in perfect understanding with the wild-type sequence in pig IGF2 intron three that has changed to GCTCA in mutant pigs (39). ZBED6 sites are found in GC-rich sequences shut to promoters with a meridian downstream of the start of transcription. An assay of histone marks in mouse C2C12 cells showed that ZBED6 primarily binds active promoters (40). Farther characterization of ZBED6 in C2C12 mouse myoblasts, mouse and human being islet cells, besides as in human colorectal cancer cell lines has demonstrated the following about ZBED6: i) it regulates IGF2 expression in a variety of cell types; 2) it has profound furnishings on transcriptional regulation; and 3) information technology acts as a transcriptional modulator that fine-tunes the expression of many genes including IGF2 (40–42). The working hypothesis is that the essential office of ZBED6 is to provide metabolic flexibility as illustrated past the grunter IGF2 mutation. Wild boars take a better power to store fat when muscle growth is not needed, whereas domestic pigs conveying the IGF2 mutation tend to shunt available energy to musculus growth.
Patterns of locomotion
The horse is particularly well suited for genetic studies of patterns of locomotion because the gait of horses is disquisitional for the different ways we use horses, e.g. equally draught horses for transporting heavy loads, equally riding horses for fast ship, or as trotting horses in front of lite carriages. All horses tin perform the iii gaits walk, trot, and gallop (Figure 2A–C). Withal, some horses tin can perform alternative gaits. Icelandic horses are a good example since they can perform two culling gaits, tölt and pace (Figure 2D and E). Tölt is a four-beat ambling gait that is almost as fast as trot but gives a much smoother ride as the horse e'er has one foot on the ground. The power to perform the tölt is an important reason for the popularity of this breed. Footstep is a 2-beat lateral gait whereas trot is a two-crush diagonal gait (Figure 2B and E). Footstep is faster than tölt, as fast equally trot, simply slower than the gallop.
Gaits in horses. (a–east): Dissimilar gaits performed past an Icelandic horse. (a): walk; (b): trot; (c): gallop; (d): tölt; and (east): step. Photos: Freyja Imsland. (f): 'Statuary pacing horse poised on a swallow with wings outstretched', bronze sculpture from Eastern Han Dynasty, most 200 Ad. Photograph: Erik Cornelius, Museum of Far Eastern Antiquities, Stockholm.
Nosotros decided to explore the genetic basis for gait variations in Icelandic horses because half of the population is classified as four-gaited (walk, trot, gallop, and tölt) and the other half is five-gaited (walk, trot, gallop, tölt, and stride). It was too known that this variation was not solely a consequence of grooming considering the ability to stride has a loftier heritability (43). However, a loftier heritability does not necessarily imply a uncomplicated, monogenic inheritance. For instance, human being pinnacle has a similar loftier heritability but is affected by hundreds of genes each with a tiny effect. We carried out a genome-wide association assay using 40 five-gaited and 30 four-gaited Icelandic horses and a SNP-chip comprising about 50,000 SNPs evenly spread beyond the genome. Remarkably, the statistical analysis revealed a single marker on chromosome 23 that showed a highly significant clan (44). Further analysis quickly revealed a unmarried base of operations modify causing a premature stop codon in DMRT3 encoding doublesex and mab-3 related transcription factor iii, which turned out to be the causative mutation. All five-gaited Icelandic horses were homozygous mutant (AA) whereas a majority of four-gaited horses were heterozygous CA, virtually 40% were homozygous mutant (AA), and a few were homozygous wild-blazon (CC) (44). It is still an open question whether lack of training or genetic modifiers explain why some homozygous mutants do not perform pace. Further analysis showed that horses used for harness racing (trot or pace) have a very loftier frequency of the Gait keeper mutation, suggesting that, in improver to promoting pace, it too inhibits the transition from trot/footstep to gallop and thereby allows horses to trot and pace at very loftier speed without galloping, which is the natural gait at high speed simply not allowed in harness racing. The Gait keeper mutation has a very strong positive effect on racing performance (44), and a diagnostic test for this mutation is at present used for horse breeding.
We performed a worldwide screen of four,396 horses representing 141 breeds for the presence of the DMRT3 mutation (45). It is present in breeds spread across Eurasia and is as well widely spread in breeds originating from N and South America. Information technology is absent-minded from breeds used every bit draught horses and in breeds where the gallop is the well-nigh important gait, such every bit Thoroughbred horses. The worldwide distribution indicates that horses carrying the Gait keeper mutation have been highly appreciated virtually probable considering of their ability to offering a smooth ride when horses were the only means of long-distance ship and for trotting at loftier speed in front end of small carriages. The worldwide distribution in combination with the presence of ancient sculptures showing horses with alternate gaits (Figure 2F) suggests that the Gait keeper mutation arose more than two,000 years before present.
The DMRT3 mutation is another example where our genetic analysis allowed us to identify the causal mutation without any prior knowledge about gene function. When we discovered this locus the function of the DMRT3 protein was unknown. It belongs to a small-scale family of transcription factors, and the most well-studied fellow member (DMRT1) has a critical function in sexual development in vertebrates, so the assumption was that the closely related DMRT3 protein had a similar office. We explored the function of DMRT3 in collaboration with Klas Kullander and his grouping at Uppsala University that has a stiff expertise in spinal cord neurobiology. DMRT3 is expressed in a specific subset of neurons in the spinal cord (now named DMRT3 neurons) in mice and horses (44). These neurons were classified as interneurons as their axons crossed the mid-line of the spinal string and they are inhibitory neurons that make direct contacts with motor neurons. Thus, these characteristics are in perfect understanding with the genetic information suggesting that these neurons play a critical function in co-ordinating musculus contractions during locomotion. Interestingly, some other group had previously developed a Dmrt3 knock-out mouse simply did not observe any striking phenotype (44). In the light of the equus caballus data and the characterization of the DMRT3 neurons nosotros decided to narrate the pattern of locomotion in these mice that appeared to move unremarkably in the cage. A detailed characterization of the pattern of locomotion on a TreadScan, limb co-ordination of newborn mice, and fictive locomotion of isolated spinal cords revealed severe defects in limb co-ordination in the Dmrt3 knock-out mice (44). Despite severe disturbances in the co-ordination of limb evolution at nativity, the Dmrt3 aught mice are able to motility normally under unstressed atmospheric condition in the cage implying that the locomotor network in the spinal string to a large extent can compensate for the loss of DMRT3. The horse and mouse information together with the functional characterization demonstrate that DMRT3 neurons accept a disquisitional function for co-ordinating limb movements in vertebrates. It is likely that the horse mutation has a more severe effect than the nada mutation present in the knock-out mouse. The equus caballus mutation causes a premature stop codon, and the mutant protein contains simply 300 out of the 474 residues in the total-length protein. The mutant poly peptide may constitute a ascendant negative form containing the Deoxyribonucleic acid-binding domain but with defect poly peptide–protein interaction. The horse mutation is partially dominant with a clear phenotypic effect in heterozygotes, admitting milder than the ane in homozygotes, whereas no pregnant phenotypic effect was found in the mice heterozygous for the null allele.
No DMRT3 mutation in humans has as nevertheless been described, but since homozygotes for the horse mutation and the mouse knock-out are fully viable information technology is very likely that humans lacking functional DMRT3 expression exist. The prediction is that they accept a mild defect in the co-ordination of limb movements. In fact, there are humans that tend to stride rather than performing the diagonal movement of legs and artillery, but no investigation has yet been carried out if this has a genetic basis. Yet, there is a previously described 225 kb deletion upstream of DMRT3 that causes a dominant course of a congenital neurodegenerative disease resembling cerebral palsy (46). It is possible that this is due to a defect in DMRT3 function. This large deletion disrupts the KANK1 factor, and 1 of the deletion breakpoints occurs simply upstream of the DMRT1 gene, which in plow is located simply upstream of DMRT3. Thus, it is possible that the deleted region contains negative regulatory elements and the emptying of these leads to overexpression or ectopic expression of DMRT3 and/or DMRT1; altered expression of DMRT1 may disturb DMRT3 function since they are expected to collaborate with identical or very similar Dna sequences (47). Information technology is probable that a disturbed development of DMRT3 neurons, which are classified as inhibitory neurons controlling the firing of motor neurons, may have severe deleterious effects on limb co-ordination. This hypothesis can exist tested using beast models carrying targeted mutations mimicking the human mutation.
Concluding remarks
Genetic and genomic studies of domestic animals are well justified due to their agricultural importance. This review illustrates how research on domestic animals can besides contribute with new basic knowledge apropos gene part and biological mechanisms. Genetic studies on domestic animals give a free view on genotype–phenotype relationships compared with what nosotros accept learned from studies on humans and experimental organisms. The reason is that domestication and breeding are evolutionary processes with stiff phenotypic selection over thousands of years. The fact that this is the near extensive genetic screen that has been accomplished ensures that studies of domestic animals will continue to enrich the field of biomedicine.
Acknowledgements
I thank all my co-workers and co-investigators for their contribution to the work described here. I thank Freyja Imsland for help in preparing the figures.
Declaration of involvement
The author reports no conflicts of involvement. Piece of work in the author'southward laboratory was supported by grants from Formas, the Swedish Enquiry Quango, Knut and Alice Wallenberg foundation, and the European Research Council.
References
1. Larson Thou, Piperno DR, Allaby RG, Purugganan MD, Andersson Fifty, Arroyo-Kalin One thousand, et al. Electric current perspectives and the future of domestication studies. Proc Natl Acad Sci Usa. 2014;111:6139–46. [PMC free commodity] [PubMed] [Google Scholar]
2. Andersson L, Böhme J, Rask Fifty, Peterson PA.. Genomic hybridization of bovine grade 2 major histocompatibility genes: 1. Extensive polymorphism of DQ alpha and DQ beta genes. Anim Genet. 1986;17:95–112. [PubMed] [Google Scholar]
3. Andersson L, Sigurdardóttir S, Borsch C, Gustafsson K.. Evolution of MHC polymorphism: extensive sharing of polymorphic sequence motifs between human being and bovine DRB alleles. Immunogenetics. 1991;33:188–93. [PubMed] [Google Scholar]
4. Imsland F, Feng CG, Boije H, Bed'hom B, Fillon 5, Dorshorst B, et al. The Rose-rummage mutation in chickens constitutes a structural rearrangement causing both altered comb morphology and defective sperm motility. PLoS Genet. 2012;8:e1002775. [PMC free article] [PubMed] [Google Scholar]
v. Hasler-Rapacz J, Ellegren H, Fridolfsson AK, Kirkpatrick B, Kirk S, Andersson L, et al. Identification of a mutation in the low density lipoprotein receptor gene associated with recessive familial hypercholesterolemia in swine. Am J Med Genet. 1998;76:379–86. [PubMed] [Google Scholar]
6. Kijas J, Bauer JTR, Gäfvert S, Marklund Due south, Trowald-Wigh G, Johannisson A, et al. A missense mutation in the b-2 integrin factor (ITGB2) causes canine leukocyte adhesion deficiency. Genomics. 1999;61:101–7. [PubMed] [Google Scholar]
7. Baranowska Körberg I, Sundström E, Meadows JRS, Rosengren Pielberg Grand, Gustafson U, Hedhammar Å, et al. A simple echo polymorphism in the MITF-M promoter is a key regulator of white spotting in dogs. PLoS One. 2014;9:e104363. [PMC free article] [PubMed] [Google Scholar]
viii. Lundén A, Marklund S, Gustafsson 5, Andersson L.. A nonsense mutation in the FMO3 gene underlies fishy off-season in cow's milk. Genome Res. 2003;12:1885–8. [PMC free article] [PubMed] [Google Scholar]
9. Bauer TRJ, Hai M, Tuschong 50, Burkholder T, Gu Y, Sokolic R, et al. Correction of the disease phenotype in canine leukocyte adhesion deficiency using ex vivo hematopoietic stalk cell cistron therapy. Claret. 2006;108:3313–20. [PMC free article] [PubMed] [Google Scholar]
10. Male monarch MC, Wilson Air conditioning.. Development at two levels in humans and chimpanzees. Science. 1975;188:107–xvi. [PubMed] [Google Scholar]
xi. Gusev A, Lee SH, Trynka G, Finucane H, Vilhjálmsson Bjarni J, Xu H, et al. Partitioning heritability of regulatory and cell-blazon-specific variants across eleven common diseases. Am J Hum Genet. 2014;95:535–52. [PMC costless article] [PubMed] [Google Scholar]
12. Gunnarsson U, Kerje Southward, Bed'hom B, Sahlqvist AS, Ekwall O, Tixier-Boichard M, et al. The Dark brown plumage color in chickens is caused by an 8.3 kb deletion upstream of SOX10. Pigment Jail cell Melanoma Res. 2011;24:268–74. [PubMed] [Google Scholar]
xiii. Pielberg M, Olsson C, Syvänen A-C, Andersson L.. Unexpectedly loftier allelic multifariousness at the KIT locus causing dominant white color in the domestic sus scrofa. Genetics. 2002;160:305–11. [PMC free article] [PubMed] [Google Scholar]
fourteen. Rubin C-J, Zody MC, Eriksson J, Meadows JRS, Sherwood East, Webster MT, et al. Whole genome resequencing reveals loci nether option during chicken domestication. Nature. 2010;464:587–91. [PubMed] [Google Scholar]
xv. Kijas JMH, Moller One thousand, Plastow Thou, Andersson L.. A frameshift mutation in MC1R and a high frequency of somatic reversions crusade black spotting in pigs. Genetics. 2001;158:779–85. [PMC free article] [PubMed] [Google Scholar]
16. Kerje S, Sharma P, Gunnarsson U, Kim H, Bagchi S, Fredriksson R, et al. The Dominant white, Dun and Smoky colour variants in chicken are associated with insertion/deletion polymorphisms in the PMEL17 cistron. Genetics. 2004;168:1507–xviii. [PMC costless article] [PubMed] [Google Scholar]
17. Zeder MA. Of kings and shepherds: specialized animal economy in Ur III Mesopotamia In: Stein G, Rothman M, editors. Chiefdoms and early states in the Near East: The organizational dynamics of complication Madison, WI: Prehistory Press; 1994. p. 175–91. [Google Scholar]
18. Fang M, Larson G, Soares Ribeiro H, Li N, Andersson L.. Contrasting mode of evolution at a coat color locus in wild and domestic pigs. PLoS Genet. 2009;5:e1000341. [PMC costless article] [PubMed] [Google Scholar]
xix. Kaelin CB, Barsh GS.. Genetics of pigmentation in dogs and cats. Ann Rev Anim Biosci. 2013;1:125–56. [PubMed] [Google Scholar]
20. Groenen MA, Archibald AL, Uenishi H, Tuggle CK, Takeuchi Y, Rothschild MF, et al. Squealer genomes provide insight into porcine demography and evolution. Nature. 2012;491:393–viii. [PMC gratis commodity] [PubMed] [Google Scholar]
21. MacLean EL, Hare B.. Dogs hijack the human bonding pathway. Scientific discipline. 2015;348:280–1. [PubMed] [Google Scholar]
22. Carneiro M, Rubin C-J, Di Palma F, Albert FW, Alföldi J, Barrio AM, et al. Rabbit genome assay reveals a polygenic ground for phenotypic change during domestication. Science. 2014;345:1074–ix. [PMC complimentary article] [PubMed] [Google Scholar]
23. Darwin C. On the origins of species past means of natural selection or the preservation of favoured races in the struggle for life. London: John Murray; 1859. [PMC gratis article] [PubMed] [Google Scholar]
24. Le Roy P, Naveau J, Elsen JM, Sellier P.. Evidence for a new major gene influencing meat quality in pigs. Genet Res. 1990;55:33–44. [PubMed] [Google Scholar]
25. Mariani P, Lundström G, Gustafsson U, Enfält Ac, Juneja RK, Andersson L.. A major locus (RN) affecting muscle glycogen content is located on squealer chromosome 15. Mamm Genome. 1996;7:52–4. [PubMed] [Google Scholar]
26. Jeon J-T, Amarger V, Robic A, Rogel-Gaillard C, Bongcam-Rudloff East, Paul S, et al. Comparative analysis of a BAC contig of the porcine RN region and the homo transcript map: implications for the cloning of trait loci. Genomics. 2001;72:297–303. [PubMed] [Google Scholar]
27. Milan D, Jeon JT, Looft C, Amarger V, Thelander Grand, Robic A, et al. A mutation in PRKAG3 associated with excess glycogen content in sus scrofa skeletal muscle. Science. 2000;288:1248–51. [PubMed] [Google Scholar]
28. Ciobanu D, Bastiaansen J, Malek M, Helm J, Woollard J, Plastow G, et al. Evidence for new alleles in the poly peptide kinase adenosine monophosphate-activated g3-subunit cistron associated with low glycogen content in pig skeletal muscle and improved meat quality. Genetics. 2001;159:1151–62. [PMC free article] [PubMed] [Google Scholar]
29. Barnes BR, Marklund S, Steiler TL, Walter Thou, Hjälm Yard, Amarger V, et al. The AMPK-gamma3 isoform has a primal role for carbohydrate and lipid metabolism in glycolytic skeletal muscle. J Biol Chem. 2004;279:38441–7. [PubMed] [Google Scholar]
thirty. Xiao B, Heath R, Saiu P, Leiper FC, Leone P, Jing C, et al. Structural footing for AMP binding to mammalian AMP-activated protein kinase. Nature. 2007;449:496–500. [PubMed] [Google Scholar]
31. Costford SR, Kavaslar N, Ahituv N, Chaudhry SN, Schackwitz WS, Dent R, et al. Gain-of-role R225W mutation in human AMPKγ3 causing increased glycogen and decreased triglyceride in skeletal musculus. PLoS One. 2007;2:e903. [PMC free commodity] [PubMed] [Google Scholar]
32. Crawford SA, Costford SR, Aguer C, Thomas SC, deKemp RA, DaSilva JN, et al. Naturally occurring R225W mutation of the gene encoding AMP-activated protein kinase (AMPK)γ3 results in increased oxidative capacity and glucose uptake in human primary myotubes. Diabetologia. 2010;53:1986–97. [PubMed] [Google Scholar]
33. Andersson Fifty, Haley CS, Ellegren H, Knott SA, Johansson G, Andersson Grand, et al. Genetic mapping of quantitative trait loci for growth and fatness in pigs. Science. 1994;263:1771–four. [PubMed] [Google Scholar]
34. Jeon J-T, Carlborg Ö, Törnsten A, Giuffra East, Amarger V, Chardon P, et al. A paternally expressed QTL affecting skeletal and cardiac muscle mass in pigs maps to the IGF2 locus. Nat Genet. 1999;21:157–viii. [PubMed] [Google Scholar]
35. Nezer C, Moreau L, Brouwers B, Coppieters West, Detilleux J, Hanset R, et al. An imprinted QTL with major consequence on musculus mass and fat degradation maps to the IGF2 locus in pigs. Nat Genet. 1999;21:155–6. [PubMed] [Google Scholar]
36. Giuffra E, Kijas JMH, Amarger V, Carlborg Ö, Jeon J-T, Andersson Fifty.. The origin of the domestic hog: contained domestication and subsequent introgression. Genetics. 2000;154:1785–91. [PMC gratis commodity] [PubMed] [Google Scholar]
37. Van Laere Equally, Nguyen Yard, Braunschweig M, Nezer C, Collette C, Moreau L, et al. A regulatory mutation in IGF2 causes a major QTL effect on muscle growth in the pig. Nature. 2003;425:832–vi. [PubMed] [Google Scholar]
38. Andersson L, Andersson 1000, Hjälm Yard, Jiang L, Lindblad-Toh K, Lindroth AM, et al. ZBED6 – the birth of a new transcription gene in the common ancestor of placental mammals. Transcription. 2010;one:144–8. [PMC free article] [PubMed] [Google Scholar]
39. Markljung Eastward, Jiang 50, Jaffe JD, Mikkelsen TS, Wallerman O, Larhammar M, et al. ZBED6, a novel transcription factor derived from a domesticated DNA transposon regulates IGF2 expression and muscle growth. PLoS Biol. 2009;7:e1000256. [PMC free article] [PubMed] [Google Scholar]
40. Jiang L, Wallerman O, Younis S, Rubin C-J, Gilbert ER, Sundström E, et al. ZBED6 modulates the transcription of myogenic genes in mouse myoblast cells. PLoS One. 2014;nine:e94187. [PMC free article] [PubMed] [Google Scholar]
41. Wang X, Jiang L, Wallerman O, Engström U, Ameur A, Gupta RK, et al. Transcription factor ZBED6 affects gene expression, proliferation, and cell expiry in pancreatic beta cells. Proc Natl Acad Sci USA. 2013;110:15997–6002. [PMC free article] [PubMed] [Google Scholar]
42. Akhtar Ali M, Younis S, Wallerman O, Gupta R, Andersson L, Sjöblom T.. Transcriptional modulator ZBED6 affects prison cell cycle and growth of human colorectal cancer cells. Proc Natl Acad Sci The states. 2015;112:7743–8. [PMC gratis article] [PubMed] [Google Scholar]
43. Albertsdóttir E, Eriksson S, Sigurdsson A, Arnason T.. Genetic assay of 'breeding field exam status' in Icelandic horses. J Anim Brood Genet. 2011;128:124–32. [PubMed] [Google Scholar]
44. Andersson LS, Larhammar One thousand, Memic F, Wootz H, Schwochow D, Rubin CJ, et al. Mutations in DMRT3 touch on locomotion in horses and spinal circuit office in mice. Nature. 2012;488:642–vi. [PMC free article] [PubMed] [Google Scholar]
45. Promerová M, Andersson LS, Juras R, Penedo MCT, Reissmann M, Tozaki T, et al. Worldwide frequency distribution of the 'Gait keeper' mutation in the DMRT3 gene. Anim Genet. 2014;45:274–82. [PubMed] [Google Scholar]
46. Lerer I, Sagi One thousand, Meiner V, Cohen T, Zlotogora J, Abeliovich D.. Deletion of the ANKRD15 factor at 9p24.3 causes parent-of-origin-dependent inheritance of familial cerebral palsy. Hum Mol Genet. 2005;14:3911–20. [PubMed] [Google Scholar]
47. Murphy MW, Zarkower D, Bardwell VJ.. Vertebrate DM domain proteins bind like Dna sequences and can heterodimerize on Dna. BMC Mol Biol. 2007;viii:58. [PMC free article] [PubMed] [Google Scholar]
48. Marklund L, Moller MJ, Sandberg One thousand, Andersson 50.. A missense mutation in the cistron for melanocyte-stimulating hormone receptor (MC1R) is associated with the chestnut coat color in horses. Mamm Genome. 1996;7:895–9. [PubMed] [Google Scholar]
49. Marklund S, Moller M, Sandberg Grand, Andersson L.. Close clan between sequence polymorphism in the KIT gene and the roan coat colour in horses. Mamm Genome. 1999;x:283–8. [PubMed] [Google Scholar]
50. Brunberg E, Andersson L, Cothran G, Sandberg M, Mikko S, Lindgren G.. A missense mutation in PMEL17 is associated with the Argent coat color in the equus caballus. BMC Genet. 2006;7:46. [PMC free article] [PubMed] [Google Scholar]
51. Rosengren Pielberg G, Golovko A, Sundström E, Curik I, Lennartsson J, Seltenhammer MH, et al. A cis-acting regulatory mutation causes premature hair greying and susceptibility to melanoma in the horse. Nat Genet. 2008;xl:1004–9. [PubMed] [Google Scholar]
52. Johansson Moller Chiliad, Chaudhary R, Hellmen E, Hoyheim B, Chowdhary B, Andersson L.. Pigs with the ascendant white coat color phenotype carry a duplication of the KIT gene encoding the mast/stem cell growth gene receptor. Mamm Genome. 1996;seven:822–thirty. [PubMed] [Google Scholar]
53. Marklund S, Kijas J, Rodriguez-Martinez H, Rönnstrand 50, Funa K, Moller Grand, et al. Molecular basis for the ascendant white phenotype in the domestic grunter. Genome Res. 1998;8:826–33. [PMC free article] [PubMed] [Google Scholar]
54. Giuffra East, Törnsten A, Marklund Due south, Bongcam-Rudloff E, Chardon P, Kijas JMH, et al. A large duplication associated with Ascendant White colour in pigs originated by homologous recombination between LINE elements flanking KIT. Mamm Genome. 2002;thirteen:569–77. [PubMed] [Google Scholar]
55. Rubin C-J, Megens H, Martinez Barrio A, Maqbool Yard, Sayyab Southward, Schwochow D, et al. Strong signatures of selection in the domestic squealer genome. Proc Natl Acad Sci U S A. 2012;109:19529–36. [PMC complimentary article] [PubMed] [Google Scholar]
56. Giuffra E, Evans G, Törnsten A, Wales R, 24-hour interval A, Looft H, et al. The Belt mutation in pigs is an allele at the Dominant white (I/KIT) locus. Mamm Genome. 1999;10:1132–half-dozen. [PubMed] [Google Scholar]
57. Kijas JMH, Wales R, Törnsten A, Chardon P, Moller Grand, Andersson 50.. Melanocortin receptor 1 (MC1R) mutations and coat colour in pigs. Genetics. 1998;150:1177–85. [PMC gratis commodity] [PubMed] [Google Scholar]
58. Drögemüller C, Giese A, Martins-Wess F, Wiedemann S, Andersson L, Brenig B, et al. The mutation causing the blackness-and-tan pigmentation phenotype of Mangalitza pigs maps to the porcine ASIP locus simply does non affect its coding sequence. Mamm Genome. 2006;17:58–66. [PubMed] [Google Scholar]
59. Kerje South, Lind J, Schütz Thou, Jensen P, Andersson 50.. Melanocortin 1-receptor (MC1R) mutations are associated with plumage colour in chicken. Anim Genet. 2003;34:241–8. [PubMed] [Google Scholar]
threescore. Keeling Fifty, Andersson L, Schütz KE, Kerje S, Fredriksson R, Carlborg Ö, et al. Plumage-pecking and victim pigmentation. Nature. 2004;431:645–six. [PubMed] [Google Scholar]
61. Gunnarsson U, Hellström AR, Tixier-Boichard Thou, Minvielle F, Bed'hom B, Ito Southward, et al. Mutations in SLC45A2 crusade feather color variation in chicken and Japanese quail. Genetics. 2007;175:867–77. [PMC gratuitous article] [PubMed] [Google Scholar]
62. Hellström AR, Sundström E, Gunnarsson U, Bed'Hom B, Tixier-Boichard M, Honaker CF, et al. Sex-linked barring in chickens is controlled by the CDKN2A/B tumour suppressor locus. Pigment Cell Melanoma Res. 2010;23:521–30. [PubMed] [Google Scholar]
63. Eriksson J, Larson G, Gunnarsson U, Bed'hom B, Tixier-Boichard M, Strömstedt L, et al. Identification of the xanthous skin factor reveals a hybrid origin of the domestic craven. PLoS Genet. 2008;four:e1000010. [PMC free article] [PubMed] [Google Scholar]
64. Dorshorst B, Molin A-M, Johansson A, Strömstedt L, Pham M-H, Chen C, et al. A complex genomic rearrangement involving the Endothelin 3 locus causes dermal hyperpigmentation in the chicken. PLoS Genet. 2011;7:e1002412. [PMC free article] [PubMed] [Google Scholar]
65. Feng C, Gao Y, Dorshorst B, Song C, Gu X, Li Q, et al. A cis-regulatory mutation of PDSS2 causes silky-plume in chickens. PLoS Genet. 2014;10:e1004576. [PMC free article] [PubMed] [Google Scholar]
66. Wright D, Boije H, Meadows JRS, Bed'hom B, Gourichon D, Vieaud A, et al. Copy number variation in intron 1 of SOX5 causes the Pea-comb phenotype in chickens. PLoS Genet. 2009;five:e1000512. [PMC free article] [PubMed] [Google Scholar]
67. Dorshorst B, Harun-Or-Rashid K, Bagherpoor AJ, Rubin C-J, Ashwell C, Gourichon D, et al. A genomic duplication is associated with ectopic eomesodermin expression in the embryonic chicken comb and two duplex-comb phenotypes. PLoS Genet. 2015;11:e1004947. [PMC complimentary article] [PubMed] [Google Scholar]
68. Wang Y, Gao Y, Imsland F, Gu X, Feng C, Liu R, et al. The crest phenotype in chicken is associated with ectopic expression of HOXC8 in cranial skin. PLoS I. 2012;7:e34012. [PMC free article] [PubMed] [Google Scholar]
69. Karlsson EK, Baranowska I, Wade CM, Salmon Hillbertz NHC, Zody MC, Andersson N, et al. Efficient mapping of mendelian traits in dogs through genome-wide association. Nat Genet. 2007;39:1321–8. [PubMed] [Google Scholar]
70. Salmon Hillbertz NHC, Isaksson G, Karlsson EK, Hellmén E, Rosengren Pielberg G, Savolainen P, et al. A duplication of FGF3, FGF4, FGF19 and ORAOV1 causes hair ridge and predisposition to dermoid sinus in Ridgeback dogs. Nat Genet. 2007;38:1318–xx. [PubMed] [Google Scholar]
71. Baranowska I, Hultin Jäderlund Yard, Nennesmo I, Holmqvist E, Heidrich N, Larsson N-Chiliad, et al. Sensory ataxic neuropathy in golden retriever dogs is caused by a deletion in the mitochondrial tRNATyr gene. PLoS Genet 2009;5:e1000499. [PMC free article] [PubMed] [Google Scholar]
72. Olsson Yard, Meadows JRS, Truvé K, Rosengren Pielberg G, Puppo F, Mauceli E, et al. A novel unstable duplication upstream of HAS2 predisposes to a breed-defining pare phenotype and a periodic fever syndrome in Chinese Shar-Pei dogs. PLoS Genet. 2011;7:e1001332. [PMC free commodity] [PubMed] [Google Scholar]
73. Dorshorst B, Henegar C, Liao 10, Sällman Almén M, Rubin C-J, Ito South, et al. Dominant cherry coat colour in Holstein cattle is associated with a missense mutation in the coatomer poly peptide complex, subunit alpha (COPA) gene. PLoS 1. 2015;x:e0128969. [PMC complimentary article] [PubMed] [Google Scholar]
74. Yusnizar Y, Wilbe Thou, Herlino AO, Sumantri C, Rachman Noor R, Boediono A, et al. MITF mutations are associated with white spotted coat color in swamp buffalo. Anim Genet. 2015;in press. [PMC free commodity] [PubMed] [Google Scholar]
Articles from Upsala Journal of Medical Sciences are provided here courtesy of Upsala Medical Society
Source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4812051/
Posted by: masonpate1995.blogspot.com
0 Response to "Are Animals For Biomedical Research Bred For Genetic Uniformity"
Post a Comment