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Coat Colour (coat + colour)

Distribution by Scientific Domains

Life Sciences	66%
Medical Sciences	33%

Terms modified by Coat Colour

coat colour pattern

Selected Abstracts

Pedigree analysis in the Austrian Noriker draught horse: genetic diversity and the impact of breeding for coat colour on population structure

JOURNAL OF ANIMAL BREEDING AND GENETICS, Issue 5 2009
T. Druml
Summary The pedigree of the current Austrian Noriker draught horse population comprising 2808 horses was traced back to the animals considered as founders of this breed. In total, the number of founders was 1991, the maximum pedigree length was 31 generations, with an average of 12.3 complete generations. Population structure in this autochthonous Austrian draught horse breed is defined by seven breeding regions (Carinthia, Lower Austria, Salzburg, Styria, Tyrol, Upper Austria and Vorarlberg) or through six coat colour groups (Bay, Black, Chestnut, Roan, Leopard, Tobiano). Average inbreeding coefficients within the breeding regions ranged from 4.5% to 5.5%; for the colour groups, the coefficients varied from 3.5% to 5.9%. Other measures of genetic variability like the effective number of founders, ancestors and founder genomes revealed a slightly different genetic background of the subpopulations. Average coancestries between and within breeding areas showed that the Salzburg population may be considered as the nucleus or original stock whereas all other subpopulations showed high relationship to horses from Salzburg. The target of draught horse breeding in the 21st century does not meet the breeding concept of maximizing genetic gains any more. Stabilizing selection takes place. In this study, we show that demographic factors as well as structure given by different coat colours helped to maintain genetic diversity in this endangered horse breed. [source]

Genetic mapping of dominant white (W), a homozygous lethal condition in the horse (Equus caballus)

JOURNAL OF ANIMAL BREEDING AND GENETICS, Issue 6 2004
C. Mau
Summary Dominant white coat colour (W) is a depigmentation syndrome, known in miscellaneous species. When homozygous in the horse (similar in mice), the mutation responsible for the white phenotype is lethal in a very early stage of gestation. It seems, that the action of the dominant white allele is not always fully penetrant, resulting occasionally in spotted look alike offspring. These horses resemble a coat colour pattern known as sabino spotting. So far, it is not known whether dominant white (W) and sabino spotting (S) share a common genetic background. In this study, a pedigree consisting of 87 horses segregating for dominant white (W) was used to genetically localize the horse (W)-locus. Microsatellite ASB23 was found linked to (W), which allowed us to map dominant white to a region on horse chromosome 3q22. Tyrosine kinase receptor (KIT) was previously mapped to this same chromosome region (3q21,22). KIT and its ligand (KITLG) are responsible for the normal function of melanogenesis, haematopoiesis and gametogenesis. So far, sequence analysis of different KIT gene fragments did not lead to new polymorphisms, except for a SNP detected in KIT intron 3 (KITSNPIn3). Additional microsatellites from ECA3q (TKY353 and LEX7), together with KITSNPIn3 allowed us to state more precisely the (W)-mutation. The positional results and comparative functional data strongly suggest that KIT encodes for the horse (W)-locus. Zusammenfassung Die dominant weisse Fellfarbe (W) ist eine Form der Depigmentierung, die bei vielen Spezies auftritt. Beim Pferd wirkt die Mutation für Dominant Weiss (W) in homozygoter Form (analog zur Maus), bereits in einem sehr frühen Stadium der Trächtigkeit letal. Es scheint, dass die Wirkung des dominant weissen Allels nicht immer mit vollständiger Penetranz erfolgt. Dies führt gelegentlich zu Nachkommen mit einer Art Schecken-Fellzeichnung. Solche Pferde sind phänotypisch mit den sogenannten ,,Sabino-Schecken,, vergleichbar. Es ist bis jetzt nicht bekannt ob Dominant Weiss (W) und Sabino-Scheckung (S) einen gemeinsamen genetischen Hintergrund besitzen. Mittels eines Pedigrees aus 87 Pferden, in dem Dominant Weiss (W) segregiert, konnte in der vorliegenden Studie der equine (W)-Locus genetisch lokalisiert werden. Der Mikrosatellit ASB23 erwies sich als gekoppelt mit (W) und ermöglichte die Zuweisung des (W)-Locus auf eine Region von Chromosom ECA 3q22. Das Gen für den Tyrosinkinaserezeptor (KIT) liegt ebenfalls in dieser Chromosomenregion (3q21,22). Das KIT -Gen ist zusammen mit dem KIT -Liganden (KITLG) verantwortlich für einen normal funktionierenden Ablauf der Melanogenese, Hämatopoese und Gametogenese. Die direkte Sequenzierung von KIT -Genfragmenten führte bis jetzt zu keinen neuen Polymorphismen, ausser einem SNP in KIT Intron 3 (KITSNPIn3). Mittels weiterer Mikrosatelliten von ECA3q (TKY353 and LEX7) sowie KITSNPIn3 gelang es, die (W)-Mutation genauer zu positionieren. Die vorliegenden Lokalisierungsresultate und vergleichende funktionelle Erkenntnisse deuten stark darauf hin, dass KIT für den Pferde (W)-Locus kodiert. [source]

Genetic diversity measures of the bovine Alberes breed using microsatellites: variability among herds and types of coat colour,

JOURNAL OF ANIMAL BREEDING AND GENETICS, Issue 2 2004
J. Casellas
Summary The Alberes population is a native bovine breed of Catalonia with an unclear origin, which historically some authors have assumed as being composed of two different colour varieties (black and fawn). Sixteen microsatellite loci were analysed, all of them included in the AIRE2066 European Concerted Action list. Overall expected and observed heterozygosities reached values of 0.649 and 0.662, respectively. Genetic differences among black and fawn varieties were not significant (FST = 0.007), and therefore the population is a single variety with a great colour gradation. On the contrary, we detected significant genetic differences among herds (FST = 0.026; p < 0.001), showing a genetic heterogeneity over short geographical distances. The number of migrants per generation among pairs of herds oscillates between 1.46 (Roig and Freixe herds) and 5.62 (Castanyers and Roig herds). Moreover, inbreeding and bottleneck situations can be rejected. The Alberes breed has been grouped within the Cantabrian trunk, closely related to the Asturiana de la Montaña and Alistana breeds, although some other breeds may also have influenced the population along its history. Zusammenfassung Die Rasse Alberes ist eine einheimische Rinderrasse Kataloniens mit unklarer Herkunft, von der historisch einige Autoren vermuten, dass sie eine Zusammensetzung aus zwei verschiedenen Farbvarianten ist (schwarz und hellbraun). Es wurden sechzehn Mikrosatelliten, die alle aus der ,,AIRE2066 European Concerted Action list,, stammen, analysiert. Der gesamte erwartete und beobachtete Heterozygotiegrad erreichte Werte von 0,649 beziehungsweise 0,662. Die genetischen Unterschiede zwischen den schwarzen und hellbraunen Varianten waren nicht signifikant (Fst = 0,007), so dass die Rasse als eine einzige Variante mit einer großen Farbabstufung gilt, die wir erhalten müssen. Im Gegensatz dazu entdeckten wir signifikante genetische Unterschiede innerhalb der Herden (Fst = 0,026, p < 0,001), die eine genetische Heterogenität innerhalb kurzer geografischer Distanzen aufzeigten. Die Anzahl an Migranten pro Generation innerhalb der Herdpaare schwankt zwischen 1,46 (Roig - und Freixe -Herden) und 5,62 (Castanyers - und Roig -Herden). Darüberhinaus kann Inzucht und eine Flaschenhalssituation zurückgewiesen werden. Die Rasse Alberes wurde innerhalb eines Cantabrischen Astes gruppiert, in enger Verwandtschaft zu den Rassen Asturiana de la Montaña und Alistana, obwohl im Laufe der Geschichte auch einige andere Rassen die Population beeinflusst haben könnten. [source]

Coat colour changes associated with cabergoline administration in bitches

JOURNAL OF SMALL ANIMAL PRACTICE, Issue 8 2003
C. Gobello
Cabergoline or bromocriptine were administered orally to 60 bitches at doses of 5 ,g/kg and 15 ,g/kg daily, respectively, for two to 45 days for the treatment of pseudopregnancy or for oestrus induction. Seven of the dogs which received cabergoline for more than 14 days developed coat colour changes from the second week of administration to the next coat shedding. Of these, fawn-coloured bitches developed a yellowish coat colour while Argentine boar hounds became black spotted, mainly on their extremities. In previous untreated oestrous periods, these bitches had shown no coat colour changes. It is concluded that a colour shift in certain haircoats of particular breeds could be mediated through the inhibition of the secretion of melanocyte-stimulating hormone by the administration of the dopaminergic agonist cabergoline for more than two weeks. Transient coat colour changes should be considered a possible side effect when planning long-term treatment with dopaminergic agonists in dogs. [source]

Heritability and complex segregation analysis of hypoadrenocorticism in the standard poodle

JOURNAL OF SMALL ANIMAL PRACTICE, Issue 1 2003
T. R. Famula
The heritability of hypoadrenocorticism (Addison's disease) was evaluated in 778 standard poodles with known Addisonian phenotypes. Addisonian status was confirmed clinically by adrenocorticotropic hormone (ACTH) challenge and 8·6 per cent of the poodles enrolled in the study were classified as being Addisonian. Hypoadrenocorticism affected both sexes with equal probability (P>0·1). The most common coat colours had a negligible effect on the incidence of hypoadrenocorticism (P>0·09), although red coat colour had a significant impact on the disease, probably due to the relatively small numbers of dogs with that coat colour. The heritability of hypoadrenocorticism in the standard poodle was estimated to be 0·75. Complex segregation analyses suggested that hypoadrenocorticism in the breed is influenced by an autosomal recessive locus. Clarification of both the heritability and mode of inheritance of hypoadrenocorticism in the standard poodle allows for better-informed breeding decisions. [source]

Biology, ecology and status of Iberian ibex Capra pyrenaica: a critical review and research prospectus

MAMMAL REVIEW, Issue 1 2009
PELAYO ACEVEDO
ABSTRACT 1The Iberian ibex Capra pyrenaica is endemic to the Iberian Peninsula and of the four subspecies originally recognized, recent extinctions mean that only two now persist. Recent genetic analyses have cast doubt on the generally accepted taxonomy of the species, where four subspecies were distinguished by coat colour and horn morphology, and propose the distinction of two subspecies based on their mitochondrial DNA sequence polymorphism. These analyses make clear the need for a comprehensive revision that integrates genetic and morphological approaches resulting in a definitive description and differentiation of the subspecies. 2Studies of ibex behavioural ecology and health status are scarce and generally descriptive. They should be implemented in an integrative way, taking into account the ecological requirements of the species, current population status, the presence of other sympatric wild and domestic ungulates, and the type of hunting regime and management in their distribution areas. 3A natural expansion of the species is currently taking place. Ibexes are present and well established in all the main mountain ranges of the Spanish Iberian Peninsula, and have recently expanded their range into the north of Portugal. Other authors estimated a total population of more than 50 000 individuals 10 years ago, distributed over more than 60 000 km2, with an average population density of 2.7 ibex/km2. However, these estimates were obtained prior to the species' recovery from recent epizootics of sarcoptic mange and should be updated. Survey methods, mainly direct count-based methods, should be adjusted to suit mountainous conditions, where it is difficult to estimate accurately the surveyed surface. 4A series of threats to ibex conservation have been identified, such as population overabundance, disease prevalence and potential competition with domestic livestock and invasive ungulates, along with negative effects of human disturbance through tourism and hunting. 5Applied ecological issues focused on the proper management of populations should be prioritized, along with the identification of current threats based on empirical, ecological data obtained from populations living in various ecological conditions in different regions. [source]

Assessing the taxonomic status of dingoes Canis familiaris dingo for conservation

MAMMAL REVIEW, Issue 2 2006
AMANDA E. ELLEDGE
ABSTRACT 1The conservation status of the dingo Canis familiaris dingo is threatened by hybridization with the domestic dog C. familiaris familiaris. A practical method that can estimate the different levels of hybridization in the field is urgently required so that animals below a specific threshold of dingo ancestry (e.g. 1/4 or 1/2 dingoes) can reliably be identified and removed from dingo populations. 2Skull morphology has been traditionally used to assess dingo purity, but this method does not discriminate between the different levels of dingo ancestry in hybrids. Furthermore, measurements can only be reliably taken from the skulls of dead animals. 3Methods based on the analysis of variation in DNA are able to discriminate between the different levels of hybridization, but the validity of this method has been questioned because the materials currently used as a reference for dingoes are from captive animals of unproven genetic purity. The use of pre-European materials would improve the accuracy of this method, but suitable material has not been found in sufficient quantity to develop a reliable reference population. Furthermore, current methods based on DNA are impractical for the field-based discrimination of hybrids because samples require laboratory analysis. 4Coat colour has also been used to estimate the extent of hybridization and is possibly the most practical method to apply in the field. However, this method may not be as powerful as genetic or morphological analyses because some hybrids (e.g. Australian cattle dog × dingo) are similar to dingoes in coat colour and body form. This problem may be alleviated by using additional visual characteristics such as the presence/absence of ticking and white markings. [source]

Seven novel KIT mutations in horses with white coat colour phenotypes

ANIMAL GENETICS, Issue 5 2009
B. Haase
Summary White coat colour in horses is inherited as a monogenic autosomal dominant trait showing a variable expression of coat depigmentation. Mutations in the KIT gene have previously been shown to cause white coat colour phenotypes in pigs, mice and humans. We recently also demonstrated that four independent mutations in the equine KIT gene are responsible for the dominant white coat colour phenotype in various horse breeds. We have now analysed additional horse families segregating for white coat colour phenotypes and report seven new KIT mutations in independent Thoroughbred, Icelandic Horse, German Holstein, Quarter Horse and South German Draft Horse families. In four of the seven families, only one single white horse, presumably representing the founder for each of the four respective mutations, was available for genotyping. The newly reported mutations comprise two frameshift mutations (c.1126_1129delGAAC; c.2193delG), two missense mutations (c.856G>A; c.1789G>A) and three splice site mutations (c.338-1G>C; c.2222-1G>A; c.2684+1G>A). White phenotypes in horses show a remarkable allelic heterogeneity. In fact, a higher number of alleles are molecularly characterized at the equine KIT gene than for any other known gene in livestock species. [source]

Mutation in the melanocortin 1 receptor is associated with amber colour in the Norwegian Forest Cat

ANIMAL GENETICS, Issue 4 2009
M. Peterschmitt
Summary Amber (previously called X-Colour) is a yellow recessive coat colour observed in the Norwegian Forest Cat (NFC) population and apparently absent in other cat breeds. Until now, there has never been any scientific evidence of yellow recessive mutation (e) reported in the extension gene in Felidae. We sequenced the complete coding sequence region for the melanocortin 1 receptor in 12 amber, three carriers, two wild-type NFCs, one wild-type European Shorthair and two ,golden' Siberian cats and identified two single nucleotide polymorphisms (SNPs): a non-synonymous (FM180571: c.250G>A) and a synonymous (FM180571: c.840T>C) mutation. The c.250G>A SNP, further genotyped on 56 cats using PCR-RFLP, is associated with amber colour and only present in the amber cat lineages. It replaced an aspartic acid with a neutral polar asparagine in the second transmembrane helix (p.Asp84Asn), a position where e mutations have already been described. Three-dimensional models were built and showed electrostatic potential modification in the mutant receptor. With these results and together with those in the scientific literature, we can conclude that amber colour in NFCs is caused by a single MC1R allele called e, which has never been documented. [source]

Molecular variation in pigmentation genes contributing to coat colour in native Korean Hanwoo cattle

ANIMAL GENETICS, Issue 5 2008
T. R. Mohanty
Summary Pigmentation genes such as TYR (tyrosinase), TYRP1 (tyrosinase-related protein 1), DCT (previously TYRP2, or tyrosinase-related protein 2), ASIP (agouti) and MC1R (melanocortin receptor 1) play a major role in cattle coat colour. To understand the genotypic profile underlying coat colour in native Korean Hanwoo cattle and Angus black cattle, portions of the above-mentioned genes were amplified. Sequence analysis revealed variation in the TYRP1 (exon 5) and MC1R genes. Restriction enzyme analysis of these two genes could distinguish between different colours of Hanwoo cattle. Quantitative estimates of melanin and eumelanin in hair from three different-coloured Hanwoo phenotypes and Angus black showed significant differences at the breed and phenotypic levels. Finally, sequence variants in MC1R were associated with total melanin and eumelanin in breeds as well as in Hanwoo phenotypes. [source]

Characterization of the porcine KIT ligand gene: expression analysis, genomic structure, polymorphism detection and association with coat colour traits

ANIMAL GENETICS, Issue 3 2008
C. Hadjiconstantouras
Summary Kit ligand (KITLG) is the ligand for the type III receptor tyrosine kinase KIT. Studies of the KIT/KITLG pathway in a number of mammalian species have shown that it is important for the development of stem cell populations in haematopoietic tissues, germ cells in reproductive organs and the embryonic migrating melanoblasts that give rise to melanocytes. Consequently, mutations in the pathway may result in a range of defects including anaemia, sterility and de-pigmentation. The cDNA sequence of the porcine KITLG gene has been reported previously, and is an attractive candidate locus for moderating coat colour in pigs. In this paper we report the gene structure and physical mapping of the porcine gene. We also report the identification of polymorphisms in the gene, one of which was used to confirm linkage to chromosome 5. Preliminary RNA expression studies using a panel of tissues have shown that in addition to the known variant lacking exon 6, there is alternative splicing of exon 4. However, little evidence was found for the KITLG gene being linked to variation in colour in a Meishan × Large White cross. [source]

Differences in the expression of the ASIP gene are involved in the recessive black coat colour pattern in sheep: evidence from the rare Xalda sheep breed

ANIMAL GENETICS, Issue 3 2008
L. J. Royo
Summary Here we have tested the hypothesis of association between different levels of agouti signalling peptide (ASIP) mRNA and the recessive black coat colour in the rare Xalda breed of sheep. To deal with this task, we first tested the possible action of both the dominant black extension allele (ED) and a 5-bp deletion (X99692:c.100_104del; Adel) in the ovine ASIP coding sequence on the black coat colour pattern in 188 Xalda individuals. The ED allele was not present in the sample and only 11 individuals were homozygous for the AdelASIP allele. All Xalda individuals carrying the Adel/Adel genotype were phenotypically black. However, most black-coated individuals (109 out of 120) were not homozygous for the 5-bp deletion, thus rejecting the Adel/Adel genotype as the sole cause of recessive black coat colour in sheep. Differences in expression of ASIP mRNA were assessed via RT-PCR in 14 black-coated and 10 white-coated Xalda individuals showing different ASIP genotypes (Awt/Awt, Awt/Adel and Adel/Adel). Levels of expression in black animals were significantly (P < 0.0001) lower than those assessed for white-coated individuals. However, the ASIP genotype did not influence the ASIP mRNA level of expression. The consistency of these findings with those recently reported in humans is discussed, and the need to isolate the promoter region of ovine ASIP to obtain further evidence for a role of ASIP in recessive black ovine pigmentation is pointed out. [source]

Endothelin receptor B2 (EDNRB2) is associated with the panda plumage colour mutation in Japanese quail

ANIMAL GENETICS, Issue 2 2007
M. Miwa
Summary The panda mutant in Japanese quail (Coturnix japonica) displays spots of wild-type plumage on a white background and is controlled by an autosomal recessive allele (s). The dotted white is controlled by a third allele (sdw) of the s locus with sdw/sdw quail having less pigmentation than s/s quail. We mapped the s locus to the Japanese quail chromosome 4 (CJA04) in a previous study. The orthologous region of the chicken (Gallus gallus) genome includes endothelin receptor B2 (EDNRB2), an avian-specific paralog of endothelin receptor B (EDNRB). EDNRB mutations in mammals retard the migration of neural crest cells (NCCs), which results in a spotted coat colour and an enteric nervous defect. In the present study, we investigated the association between the s locus and EDNRB2 in Japanese quail. Sequence comparison among transcripts from livers of wild-type, panda and dotted white quail revealed a nucleotide substitution (c.995G>A) leading to a p.R332H amino acid change that was specific to panda, whereas no amino acid substitution was found in dotted white birds. The amino acid position 332 is located in the sixth transmembrane domain and is highly conserved in both avian and mammalian endothelin receptors. The A allele at nucleotide position 995 was specific to panda (s/s) birds among 10 strains, and was mapped to the same chromosomal region as the s locus. Quantitative RT-PCR revealed that EDNRB2 transcripts were reduced in both panda and dotted white mutants compared with wild-type. However, there was no difference between the early embryos of wild-type and panda with respect to the migration of NCCs. The genetic association of EDNRB2 with plumage colour in birds was found for the first time in this study. [source]

Mutations in the melanocortin 1 receptor (MC1R) gene are associated with coat colours in the domestic rabbit (Oryctolagus cuniculus)

ANIMAL GENETICS, Issue 5 2006
L. Fontanesi
Summary We sequenced almost the complete coding region of the MC1R gene in several domestic rabbits (Oryctolagus cuniculus) and identified four alleles: two wild-type alleles differing by two synonymous single nucleotide polymorphisms (c.333A>G;c.555T>C), one allele with a 30-nucleotide in-frame deletion (c.304_333del30) and one allele with a 6-nucleotide in-frame deletion (c.280_285del6). A polymerase chain reaction-based protocol was used to distinguish the wild-type alleles from the other two alleles in 263 rabbits belonging to 37 breeds or strains. All red/fawn/yellow rabbits were homozygous for the c.304_333del30 allele. This allele represents the recessive e allele at the extension locus identified through pioneering genetic studies in this species. All Californian, Checkered, Giant White and New Zealand White rabbits were homozygous for allele c.280_285del6, which was also observed in the heterozygous condition in a few other breeds. Black coat colour is part of the standard colour in Californian and Checkered breeds, in contrast to the two albino breeds, Giant White and New Zealand White. Following the nomenclature established for the rabbit extension locus, the c.280_285del6 allele, which is dominant over c.304_333del30, may be allele ED or allele ES. [source]

Polymorphism at the porcine Dominant white/KIT locus influence coat colour and peripheral blood cell measures

ANIMAL GENETICS, Issue 4 2005
A. Johansson
Summary We have examined the phenotype of different KIT genotypes with regard to coat colour and several blood parameters (erythrocyte numbers and measures, total and differential leucocyte numbers, haematocrit and haemoglobin levels and serum components). The effect of two different iron supplement regimes (one or two iron injections) on the blood parameters was also examined. For a total of 184 cross-bred piglets (different combinations of Hampshire, Landrace and Yorkshire) blood parameters were measured four times during their first month of life, and the KIT genotypes of these and 70 additional cross-bred piglets were determined. Eight different KIT genotypes were identified, which confirms the large allelic diversity at the KIT locus in commercial pig populations. The results showed that pigs with different KIT genotypes differ both in coat colour and in haematological parameters. In general, homozygous Dominant white (I/I) piglets had larger erythrocytes with lower haemoglobin concentration, indicating a mild macrocytic anaemia. The effect of two compared with one iron injection was also most pronounced for the I/I piglets. [source]

TYRP1 is associated with dun coat colour in Dexter cattle or how now brown cow?

ANIMAL GENETICS, Issue 3 2003
T. G. Berryere
Summary Tyrosinase related protein 1 (TYRP1), which is involved in the coat colour pathway, was mapped to BTA8 between microsatellites BL1080 and BM4006, using a microsatellite in intron 5 of TYRP1. The complete coding sequence of bovine TYRP1 was determined from cDNA derived from skin biopsies of cattle with various colours. Sequence data from exons 2,8 from cattle with diluted phenotypes was compared with that from non-diluted phenotypes. In addition, full-sib families of beef cattle generated by embryo transfer and half-sib families from traditional matings in which coat colour was segregating were used to correlate TYRP1 sequence variants with dilute coat colours. Two non-conservative amino acid changes were detected in Simmental, Charolais and Galloway cattle but these polymorphisms were not associated with diluted shades of black or red, nor with the dun coat colour of Galloway cattle or the taupe brown colour of Braunvieh and Brown Swiss cattle. However, in Dexter cattle all 25 cattle with a dun brown coat colour were homozygous for a H424Y change. One Dexter that was also homozygous Y434 was red because of an ,E+/E+' genotype at MC1R which lead to the production of only phaeomelanin. None of the 70 remaining black or red Dexter cattle were homozygous for Y434. This tyrosine mutation was not found in any of the 121 cattle of other breeds that were examined. [source]

Molecular tests for coat colours in horses

JOURNAL OF ANIMAL BREEDING AND GENETICS, Issue 6 2009
Stefan Rieder
Summary Colour phenotypes may have played a major role during early domestication events and initial selection among domestic animal species. As coat colours mostly follow a relatively simple mode of Mendelian inheritance, they have been among the first traits to be systematically analysed at the molecular level. As a result of the number of genetic tools developed during the past decade, horse coat colour tests have been designed and are now commercially available for some of the basic phenotypes. These tests enable breeders to verify segregation within particular pedigrees, to select specific colour phenotypes according to market demand or studbook policies and to avoid complex inherited diseases associated with some of the colour patterns. This paper reviews the relevance of the topic, describes all currently available tests for coat colours in horses and addresses also ongoing research in this field. [source]

Pedigree analysis in the Austrian Noriker draught horse: genetic diversity and the impact of breeding for coat colour on population structure

Heritability and complex segregation analysis of hypoadrenocorticism in the standard poodle

Genetic heterogeneity and selection signature at the KIT gene in pigs showing different coat colours and patterns

ANIMAL GENETICS, Issue 5 2010
L. Fontanesi
Summary Mutations in the porcine KIT gene (Dominant white locus) have been shown to affect coat colours and colour distribution in pigs. We analysed this gene in several pig breeds and populations (Sicilian black, completely black or with white patches; Cinta Senese; grey local population; Large White; Duroc; Hampshire; Pietrain; wild boar; Meishan) with different coat colours and patterns, genotyping a few polymorphisms. The 21 exons and parts of the intronic regions were sequenced in these pigs and 69 polymorphisms were identified. The grey-roan coat colour observed in a local grey population was completely associated with a 4-bp deletion of intron 18 in a single copy KIT gene, providing evidence that this mutation characterizes the Id allele described in the early genetic literature. The white patches observed in black Sicilian pigs were not completely associated with the presence of a duplicated KIT allele (Ip), suggesting that genetic heterogeneity is a possible cause of different coat colours in this breed. Selection signature was evident at the KIT gene in two different belted pig breeds, Hampshire and Cinta Senese. The same mutation(s) may cause the belted phenotype in these breeds that originated in the 18th,19th centuries from English pigs (Hampshire) and in Tuscany (Italy) in the 14th century (Cinta Senese). Phylogenetic relationships of 28 inferred KIT haplotypes indicated two clades: one of Asian origin that included Meishan and a few Sicilian black haplotypes and another of European origin. [source]

Mutations in the melanocortin 1 receptor (MC1R) gene are associated with coat colours in the domestic rabbit (Oryctolagus cuniculus)

Localizing the X-linked orange colour phenotype using feline resource families

ANIMAL GENETICS, Issue 1 2005
R. A. Grahn
Summary Many genes influencing mammalian coat colours are well conserved. While genes responsible for pelage phenotypes in one species provide strong evidence for a candidate gene in a different species, the X-linked orange phenotype of the domestic cat is unique within mammals. The orange locus (O) undergoes X-inactivation, producing females that express both wildtype black (wt) and orange (variant) phenotypes when heterozygous (tortoiseshell). The orange locus has not yet been localized on the X chromosome. Tortoiseshell male cats have been identified but have been shown to be sex chromosome trisomies (XXY). To localize the cat orange locus, 10 feline-derived X-linked microsatellites were analysed in two extended cat pedigrees consisting of 79 and 55 individuals, respectively, segregating for the orange phenotype. Linkage analyses excluded close association of orange in the vicinity of the nine informative X-linked microsatellites. One marker was not polymorphic within either family. Several markers suggested exclusion (Z < ,2.0) at distances of 7.5,33 cM. Exclusion analyses suggested a possible location for orange a 14 cM region near Xcen. Recombination distances of markers in the segregating feline pedigrees were reduced as compared with the feline interspecies backcross family. Thus, the presented pedigrees may be useful as reference families for the domestic cat because more accurate recombination rates for domestic cats can be determined. [source]