White spotting can cause blue eyes, microphthalmia, blindness and deafness; however, because pigmentation is generally retained around the eye/ear area, this is rare except among, The greying gene affects both eumelanin, and to a lesser extent phaeomelanin. Dilution of Eumelanin and/or Phaeomelanin Caused by MLPH Mutations. A Missense Mutation in SLC45A2 is Associated with Albinism in Small Long Haired Dogs. [64] 7 of those are identified as being of key importance and each results in ~2x difference in body weight. If a dog has any of the genes to turn its black eumelanin into liver, blue or isabella then all of the black in its coat will be changed. Each gene has a unique, fixed location, known as a locus, within the dog genome. [26] There are three known alleles that occur at the K locus: The dominance hierarchy for the K locus alleles appears to be as follows: KB > kbr > ky. Alleles at the Agouti (A), Extension (E) and Black (K) loci determine the presence or absence of brindle and its location: † eh and EG are only included in the table where their interactions are known. Recessive black is a rare gene exhibited by a few dog breeds, such as the Shetland Sheepdog and German Shepherd. The dominance hierarchy for the E locus alleles appears to be as follows: Em > EG/d > E > eh > e. The alleles at the K locus (the β-Defensin 103 gene or DEFB103) determine the coloring pattern of an animal's coat. Sample collection kits are available and can be ordered at Canine Test Now. For normal Yorkshire Terriers Piebald spotting sp sp is not allowed. However, the overall coat type of this dog is dependent on the combination of this dog's genotypes at the L, Cu, and IC loci. As only ee appears capable of keeping eumalanin out of the coat, this means that a dominant black dog must have either E or E m in its genetic makeup. This dog does not carry the Mutation for weak furnishings or improper coat and will therefore have furnishings (proper coat). The inner rings show the hidden color genes carried by the dog. These breeds possess distinct traits related to … Each follicle also holds a variety of silky- to wiry-textured secondary hairs (undercoat) all of which are wavy, and smaller and softer than the primary hair. In dog coat colour genetics, there are many unknown mechanisms that lead to the expression of some colour phenotypes other than the basic colours (for example, ticking, progressive greying and tweed phenotypes). All black areas on a dog are caused by cells producing eumelanin. It can also affect only the areas of a dog that would have been reddish and not affect the black areas, i.e. This quiz includes questions on basic dog coat color genetics. [12] Spatial-dependent signaling results in parts of the body with different levels of each pigment. Examples of this type of coat include the Korthals Griffon and possibly the Irish Wolfhound. This panel of coat color and fur type tests is specifically tailored to the Havanese breed. For more information on the genetics of coat types click here. MC1R including Mask, Grizzle, and Red/Cream (E Locus), Interdental/GUM brushes supplied by owner, Cytology Brush-supplied by VGL at no additional charge. A general understanding of Mendelian genetics may be required for some questions. When distinguishing breed from type, the rule of thumb is that a breed always "breeds true". As such, multiple commercial testing laboratories include basic color alleles in their popular screening panels, allowing for the creation of genotyped datasets at a scale not before appreciated in canine genetic research. The alleles at the W locus (the R-spondin-2 gene or RSPO2) determine the coarseness and the presence of "facial furnishings" (e.g. This webpage is part of a series on Dog Coat Color Genetics and was last updated on 28 July 2020 by Sheila Schmutz, when it was moved to a different server. The dog’s coat color can also impact whether the dog’s eye color appears true to shade. A variant in the Keratin-71 gene is associated with curly hair in dogs. A dog breed is a particular strain or dog type that was purposefully bred by humans to perform specific tasks, such as herding, hunting, and guarding. Hayward JJ et al. The German Shepherd Dog is one breed that should definitively look masculine or feminine. Two alleles are theorised to occur at the I locus: It is thought that I and i interact with semi-dominance, so that there are three distinct phenotypes. Dominant and recessive alleles Several gene variants are known to produce dilute coloration in dogs. Miscolours occur quite rarely in dog breeds, because genetic carriers of the recessive alleles causing fur colours that don't correspond to the breed standard are very rare in the gene pool of a breed and there is an extremely low probability that one carrier will be mated with another. Dreger DL, Parker H, Ostrander E, Schmutz SM. By Claudia Kawczynska, April 2020. In fact, the combination of these genes explains the coat traits of 90 percent of AKC registered dog breeds. Goldendoodle types. Alleles present at the Spotting (S), Ticking (T) and Flecking (F) loci determine white markings. For example, it is unclear if the brindle pattern is part of the E (Extension) genes series (expressed e br ) or part of another gene series K (expressed K br .) Dog coat colors affect various factors including the canine’s olfaction ability. The alleles postulated are: S is incomplete dominant (towards co-dominant) to sp. For example the dilute gen D in the suddenly appeared variety "silver coloured" Labrador Retriever might probably come from a Weimaraner. Journal of Heredity 106:285-8. Defective MLPH prevents normal pigment distribution, resulting in a paler colored coat.[8]. Canis lupus familiaris is one of the most beloved pet species with hundreds of world-wide recognized breeds, which can be differentiated from each other by specific morphological, behavioral and adoptive traits. This dog will pass F (furnishings, proper coat) to 100% of its offspring. Type in your dog’s breed and hit "Search" to see the possibilities. For … A newer book "The Genetics of the Dog", 2nd Edition (2012), edited by E.A. These data were compared with descriptions of various coat types. Punnett square: Inheritance with one carrier of a recessive gene. Rarely, the entire coat is affected resulting in an albino dog with red eyes. that you understand what is meant by the terms 'gene', 'allele', 'phenotype' etc. [42] The cream-white colour of the Shiba Inu is not caused by any spotting gene but by strong dilution of pheomelanin. Dogs with Genotype ee can only store pheomelanin in the fur. Low shedding, tight coats, and lack of a double coat are perceived as key traits contributing to the perceived “hypoallergenic” nature of established breeds like the Bichon Frisé, Portuguese water dog, and POOD. Most black dogs are of this type… A research project at the University of Saskatchewan Genetic Research Laboratory has, at least partially, identified the actual genetic mechanisms behind white and cream colored coats in several breeds of domestic dog, including white coat dogs from German Shepherd breed lines. Salmon Hillbertz N H C, Isaksson M, Karlsson E K, Hellmen E, Rosengren Pielberg G, Savolainen P, Wad C M, von Euler E, Gustafson U, Hedhammar A, Nilsson M, Lindblad-Toh K, Andersson L, Andersson G (2007): "Duplication of FGF3, FGF4, FGF 19 and ORAOV1 causes hair ridge and predisposition to dermoid sinus in, Ridgeback dogs" in Nature Genetics, Vol. With respect to coat texture, shedding, follicle density and number of secondary hairs per follicle, heterozygotes closely resemble animals homozygous for the mutant allele, with minor differences. There are two common alleles: D (normal, wild-type MLPH), and d (defective MLPH) that occur in many breeds. In the breed Boxer large white markings in heterzygous carriers with genotype S si or S sw belong to the standard colours, therefore extreme white Boxers are born regularly, some of them with health problems. The alleles at the R locus (the keratin-71 gene or KRT71) determine whether an animal's coat is straight or curly. Different Types of Dog Coats. The Two Most Important Breeding Selection Criteria For a serious and responsible breeder of Anatolian Shepherd Guardian Dogs, the two most important breeding selection criteria are proven livestock working ability and superior flock-guardian temperament. Dogs that are heterozygous for the … Genetics expands the range of these two colors. In case two carriers have offspring, according to the law of segregation an average of 25% of the puppies are homozygous and express the off-colour in the phenotype, 50% become carriers and 25% are homozygous for the standard colour. (30-40 kg) * … Mostly seen in breeds with long or non-shedding coats. These crosses are fully coated and heterozygous for AHT-hairlessness. IGF1R (Insulin-like growth factor 1 receptor) and HMGA2 (High-mobility group AT-hook 2) are incomplete dominant with delicate dwarfs vs compact large dogs and heterozygotes closer to the homozygous dwarfed phenotypes. A dominant allele will completely cover up a recessive allele. Eyes- not affected. Canine coat color is a readily observed phenotype of great interest to dog enthusiasts; it is also an excellent avenue to explore the mechanisms of genetics and inheritance. The various dog coat colors are from patterns of: By 2020, more than eight genes in the canine genome have been verified to determine coat color. Se (seal). [43] Melanocytes are present in the whole skin and in the embryonic tissue for the auditory organs and eyes, therefore this colour is not associated with any health issues. Time-dependent pigment switching can lead to the production of a single hair with bands of eumelanin and phaeomelanin. Furnishings and Improper Coat A dominant variant of the R-spondin-2 gene produces the longer mustache and eyebrows seen in wire-haired dogs and other breeds. The Afghan Hound has a unique patterned coat that is long with short patches on the chest, face, back and tail. When these 2 dogs are crossed there is a wide range of possibilities that could occur because of the different genetic makeup. [56] There are coated homozygous dogs in all hairless breeds, because this type of inheritance prevents the coat type from breeding true. For example, a dog described as red, black and white could be a black-and-tan dog with … beard, moustache, eyebrows). There are four different bases found in DNA and these are named adenine (A), guanine (G), cytosine (C) and thymine (T). Type of dominance- Complete. Patterns of medium-sized individual spots, smaller individual spots, and tiny spots that completely cover all white areas leaving a roan-like or merle-like appearance (reserving the term large spots for the variation exclusive to the Dalmatian) can each occur separately or in any combination. This article assumes you are familiar with basic Mendelian genetics- i.e. [34], In 2014, a study found that a simple repeat polymorphism in the MITF-M Promoter is a key regulator of white spotting and that white color had been selected for by humans.[36][37]. Agouti (A Locus) The Agouti Signaling Protein (ASIP) gene interacts with the MC1R gene to control red and black pigment switching in dogs, affecting amount, type, and distribution of the two pigments. E Locus: … [27] The H locus is a modifier locus (of the M locus) and the alleles at the H locus will determine if an animal expresses a harlequin vs merle pattern. Dog coat color genetics Today’s scientists and breeders are familiar with locations on chromosomes, or loci, responsible for appropriate dog coat color, which in turn depends on the dog’s descent. First up is his six-minute video lesson decoding the role that three genes play in determining a dog’s coat, the length of fur short or long, the texture wirey, curly or … 7, 10460. DNA studies have isolated a missense mutation in the 20S proteasome β2 subunit at the H locus. Dog Coat Color - French Bulldog Panel. [47] The same applies for Dobermann Pinschers suffering from Blue dog syndrome.[48][49][50]. This panel of coat color tests is … ASIP (the A locus) binds to and inactivates MC1R, thereby causing phaeomelanin synthesis. If you would like credit for your photo or if you do not want your photo displayed here, please email me at hazelwoodbc@gmail.com. W/W dogs have coarse hair, prominent furnishings and greatly-reduced shedding. This basic dog coat color panel bundles together several genetic tests for coat color that are applicable to all breeds. We are the first to describe coat colour … The alleles at the A locus are related to the production of agouti signalling protein (ASIP) and determine whether an animal expresses an agouti appearance, and, by controlling the distribution of pigment in individual hairs, what type of agouti. This dog … Several genetic mutations that prevent normal functioning of vWF have been identified. Genotypes of dogs of these 3 breeds are usually L/L or L/l, which does not match with their long-haired phenotype. Dog coat color is governed by how genes are passed from dogs to their puppies and how those genes are expressed in each dog. The wool coat type is the most like a typical Poodle coat – dense, wiry, curly and mostly non-shedding. Dog Coat Colour Genetics: A Review. Please note that the photos on this webpage are from dogs that were actually genotyped using DNA and therefore are verified to have the alleles that they are shown to represent. Heterozygosity for a Short INterspersed Element (SINE) insertion in canine PMEL causes a striking pigmentation pattern, known as merle, that is unique to domesticated dogs. The Yorkshire and Silky Terriers share common ancestry and likely share an unidentified gene responsible for their long hair. These mutations are associated with different clinical bleeding disorders known as vWD Type 1, Type 2, and Type 3. vWD Type 1 is the most common bleeding disorder among dogs and is present in several breeds. Played 2,496 times. However, there are genes which turn eumelanin into other colours - liver (brown), blue (grey), or isabella (a dusty pale brown). One of the genes involved in the production of these pigments in many species including dogs is Melanocortin 1 Receptor (MC1R) which is also known as the Extension locus. Dog fur is colored by two types of melanin: eumelanin (brownish-black) and phaeomelanin (reddish-yellow). To understand why a dog’s coat looks the way it does based on its genes requires an understanding of a handful of particular dog coat genes and their alleles. White spotting also affects skin, causing pink patches. Usually only one or a small number of alleles exist for each gene. And the usual rules apply—most genes come in pairs, one from the dog’s mother and one from its father. This gene was found to be MFSD12 in 2019. Goldendoodle is a mix between a Golden Retriever and a Poodle both being popular and great dogs. Ostrander and A. Ruvinsky contains a chapter entitled "Molecular Genetics of Coat Colour Texture and Length in the Dog" by Christopehre B. Kaelin and Gregory S. Barsh. Each of these has at least two known alleles. While a single coated long and curly haired dog fits into 3 categories (single coat + long hair + curly texture). Research indicates that the majority of variation in coat growth pattern, length and curl can be attributed to mutations in four genes, the R-spondin-2 gene or RSPO2, the fibroblast growth factor-5 gene or FGF5, the keratin-71 gene or KRT71[2] and the melanocortin 5 receptor gene (MC5R). As of Feb 05 21. Entries in the table show the probabilities of producing various coat color within a litter. This panel of coat color tests is specifically tailored to the Bulldog breed. Dog Coat Colour Genetics. Coat color and type are essential characteristics of domestic dog breeds. … The Agouti Signaling Protein (ASIP) gene interacts with the MC1R gene to control red and black pigment switching in dogs, affecting amount, type, and distribution of the two pigments. As of Feb 05 21. Within each strand of DNA are genes. g (no progressive graying). 2015. For example, skin spots on a piebald-spotted dog will not match up with the spots in the dog's coat; and a merle dog with one blue eye can just as likely have better eyesight in its blue eye than in its brown eye. Six known variants of this gene are responsible for producing markings and coat colors including melanistic mask, grizzle/domino, black, and shades of red/yellow. Six known variants of this gene are responsible for producing markings and coat colors including melanistic mask, grizzle/domino, black, and shades of red/yellow. Females are shorter, lighter, and narrower through the face and muzzle area. The ABCs of Dog Genetics. Learn more about how DNA testing and dog color genetics can help you get beautiful, healthy puppies. Cheek brush DNA samples (Epicentre, Madison, WI) from 11 dog families that segregated for cream coat color were obtained from dog breeders and owners and used for genotyping. Black masks, if present, are not affected. There are two known alleles that occur at this locus: 23–26 inches (60–65 cm) tall at the withers; Weight between 66–88 lbs. [2] There are two known alleles that occur at the W locus: W is dominant to w, but the dominance of W > w is incomplete. This dog carries two copies of k y which allows for the expression of the agouti gene (A locus) which can result in a variety of coat colors including sable/fawn, tricolor, tan points, black or brown. A dominant variant of the R-spondin-2 gene produces the longer mustache and eyebrows seen in wire-haired dogs and other breeds. Figure 1: Experimenting with thousands of garden peas, Johann Gregor Mendel uncovered the fundamentals of genetics. The ratio of primary to secondary hairs varies at least six-fold, and varies between dogs according to coat type, and on the same dog in accordance with seasonal and other hormonal influences. These vast … Dog Colors & Coat Patterns Find dog breeds with a particular coat color or pattern. The colour varieties seen in dogs are due to genes controlling the amount, extent, and … Cat Submission … This basic dog coat color panel bundles together several genetic tests for coat color that are applicable to all breeds. ?Seal Locus: Brown undertone without expressing bb. "What's important for human health is the way we found the genes involved in dog coats and figured out how they work together, rather than the genes themselves," said Elaine A. Ostrander, Ph.D., chief of the Cancer Genetics Branch in NHGRI's … DNA studies are yet to confirm the existence of these genes or alleles but their existence is theorised based on breeding data:[40]. Price. greys at a young age is not caused by, The effect of the ticking gene(s) is to add back little coloured spots to areas made white by piebald spotting (, The mutant allele (reduced shedding, single coat or minimal undercoat, reduced length), The wildtype allele (normal shedding, double coat, normal length), In dogs with long curly coats with furnishings (, This page was last edited on 14 December 2020, at 02:29. The alleles at the S locus (the microphthalmia-associated transcription factor gene or MITF) determine the degree and distribution of white spotting on an animal's coat. Corded coats will form naturally, but can be messy and uneven if not "groomed to cord" while the puppy's coat is lengthening. Teeth are affected as well, and hairless dogs have incomplete dentition. When conceived, a dog receives two copies of DNA—one from the father and one from the mother. [52] Puppies are born with a single coat, with more hair follicles per unit area, but each hair follicle contains only a single hair of fine, silky texture. The gene at the B locus is known as tyrosinase related protein 1 (TYRP1). Merle is dominant, so a dog can me MM or Mm to be merle. But only 8 genes in the dog are associated with coat color. Dogs with Genotype EE or Ee can produce black or chocolate brown eumelanin for the fur. Promotional pricing until December 31, 2021: $115 per animal Home; DNA Tests; Dog; Dog Coat Color - French Bulldog Panel Description. Genetics 101: How Dogs Inherit Traits. Development of the adult coat begins around 3 months of age, and is completed around 12 months. 2016 Complex disease and phenotype mapping in the domestic dog. Other genes modify how much eumelanin and phaeomelanin are … BB or Bb on the B locus still allows a black nose. By the end of this section, you will be able to: Describe the molecular basis of inheritance. The ridge is caused by a duplication of several genes (FGF3, FGF4, FGF 19, ORAOV1 and sometimes SNP), and ridge is dominant to non-ridged. Various people have postulated several alleles at the C locus and suggested some/all determine the degree to which an animal expresses phaeomelanin, a red-brown protein related to the production of melanin, in its coat and skin. On the contrary, this article will focus on dog coat colors which are typically seen around … There are two known alleles that occur at this locus: The mutant allele is incomplete dominant. Furnishings are a dominant trait, meaning that a dog only needs to have one copy of the Furnishings gene to show that physical trait. In this type of inheritance, there are two alleles: dominant and recessive. Wool Labradoodle coat type. Dog Coat Color and Hair Traits; Dog Genetics 1.0: The Basics; Dog Genetics 2.0: Colours; Dog Genetics 2.1 Colours Chart; Dog Genetics 3.0: Simple Genetic Diseases ; Dog Genetics 4.0: Evolution, Breeds, Breeding strategies and Inbreeding; Dog Genetics 4.1: Inbreeding Calculator, Detailed Instructions and Interpretation; Veterinary Continuing Education – Dog Genetics Demystified; Cat. The breeds of domestic dog, Canis lupus familiaris, display a range of coat types with variation in color, texture, length, curl, and growth pattern. The development of coat colour, skin colour, iris colour, pigmentation in back of eye and melanin-containing cellular elements of the auditory system occur independently, as does development of each element on the left vs right side of the animal. Five alleles have been theorised to occur at the C locus: However, the C locus is now considered to be the gene SLC45A2 The Hungarian Wirehaired Vizsla shown above is an example of the wirehair gene on a smooth-coated dog. Present and decipher information about inheritance using a pedigree. For example, with Labrador Retrievers there are three (3) accepted coat color phenotypes (what you can see): Black, Yellow, and Chocolate. Fleece … The wild-type coat in dogs is short, double and straight. Pattern Genes: genes that affect the distributionof a particular color. (credit: … The AHT gene, serum/glucocorticoid regulated kinase family member 3 gene (SGK3), is recessive and does not result in missing teeth. There are 100's of dog breeds in existence, and no two dogs are exactly the same. So, at any one gene locus a dog will either be homozygous, that is, the gene is made of two identical alleles (one from its mother and one its father) or heterozygous, that is, the gene is made of two different alleles (again, one inherited from each parent). This gene affects the color of the eumelanin pigment produced, making it either black or brown. There are 8 major genes and their variants responsible for huge diversity in dog coat color. Some breeds of dog do not grow hair on parts of their bodies and may be referred to as "hairless". For the Beagle tricolor Genotype sp sp is the first colour in the breed standard. Color Genes: genes that affect the pigment colorof hairs; OR 2. When you consider dachshund hair type/colors/patterns and the genetics involved, you need to realize some of what we know is an exact science and some is theory. There are two alleles that occur at the M locus: M and m show a relationship of both co-dominance and no dominance. Two alleles are theorised to occur at the F locus: (Please see ticking below, which may be another name for the flecking described here), It is thought that F is dominant to f.[35]. The alleles at the theoretical I locus are thought to affect phaeomelanin expression. Furnishings, shedding, and curls are all genetic. Genetics: Dog Coat Color Learning Objectives. is significantly reduced by, The merle gene also affects the skin, eye colour, eyesight and development of the eye and inner ear. Researchers have not yet assigned a letter to this locus and "R" has been selected based on the use of the term "Rex" for curled hair in domestic cats. These phases are: Most dogs have a double coat, each hair follicle containing 1-2 primary hairs and several secondary hairs. Trying to guessotype from a word description about the coat color of a dog is especially hazardous. Even good guessotyping is prone to flaws when the photos are not great or the dog is a breed that has several possible genotypes associated with the same phenotype, or worse is of a phenotype that changes with age. The genes that interest us can be broadly classified as either: 1. There are four known alleles that occur at the B locus: The melanophilin gene (MLPH) at the D locus causes a dilution of both eumelanin and phaeomelanin and determines the intensity of pigmentation. The alleles at the theoretical F locus are thought to determine whether an animal displays small, isolated regions of white in otherwise pigmented regions (not apparent on white animals). In the Portuguese Water Dog, dogs without furnishings are referred to as having an "Improper Coat." Coat Colours As with other mammals, dogs have two major types of pigment in their coat: dark pigment (Eumelanin) which is responsible for black and brown in the pigmented areas, and yellow pigment (Phaeomelanin) which is responsible for red, yellow, orange, golden, cream, apricot in the pigmented areas. The combination of alleles a dog has is known as the genotype. Since a dog needs to be aa for this to work, it explains why pure black in these breeds is rare. leaving a cream Afghan with a very black mask. Dog Color Genetics. Conclusions. Wavy hair is considered desirable in several breeds, but because it is heterozygous, these breeds do not breed true for coat type. Blue. SE (normal black). Expect plenty of at-home and professional brushing and grooming! The alleles at the L locus (the fibroblast growth factor-5 gene or FGF5) determine the length of the animal's coat. Wijesena, H.R. DNA studies have not yet confirmed the existence of all four alleles, with some research suggesting the existence of at least two alleles (S and sp)[31] and other research suggesting the possible existence of a third allele (si). There are two alleles that occur at the H locus: H/h heterozygotes are harlequin and h/h homozygotes are non-harlequin. Genes associated with hair length, growth and texture. TYRP1 is an enzyme involved in the synthesis of eumelanin. These interactions affect the distribution of two major types of melanin - Phaeomelanin and Eumelanin. This means that its sense of smell is affected by its coat color mainly due to genetics. This dog will pass one copy of As to 100% of its offspring and can produce saddle tan dogs. The Irish Water Spaniel may share the same pattern gene, although unlike the Afghan Hound, the IWS is otherwise genetically a long-haired (fixed for l/l) breed. The merle pattern is labeled “red” or “blue.” The merle forms … Which pieces of DNA a dog inherits from each parent is completely random. Knowledge of the genetics of canine coat coloring and patterning[1] and coat texturing and length[2] has improved a great deal in recent years. Back has darker hairs. A dog with an elongated skull is dolichocephalic. Homozygous ee causes red or yellow fur. [39] Please see also http://munster.sasktelwebsite.net/DogColor/white.html, There are additional theoretical loci thought to be associated with coat color in dogs. Limb Length Locus: Micromelic achondroplasia produces shortened limbs but leaves other body proportions alone. Dogs with the curl variant have curly coats or wavy coats depending on how many copies of the variant they possess. [58] Software is also available to assist breeders in determining the likely outcome of matings.[59]. Males are taller, heavier, and squarer through the face. Determine the outcome in crosses involving complete dominance. June 1, 2012. If eumelanin is absent in the eyes, the dog has blue eyes. Nose- not affected. Mammals have two pigments that are the basis of hair color: eumelanin (black) and phaeomelanin (red or yellow). Panel can be purchased on MyVGL. A dog’s genetic instructions are stored as a type of code that is made up of units called bases. Two alleles are theorised to occur at the G locus: The alleles at the theoretical T locus are thought to determine whether an animal displays small, isolated regions of pigment in otherwise s-spotted white regions. This research laboratory also searched for and has not found tyrosinase malfunction in white coat dogs common to those … Dogs are the most variable mammal on earth, with artificial selection producing around 450 globally recognized dog breeds. Several genes are at work here, and they all interact. For example, if your results show that your dog is a Type VI, your dog is a yellow dog with a black [46], The occurrence of a dominant coat colour gene not belonging to the standard colours is a suspicion for crossbreeding with another breed.