Standard Doberman Color Information
Written by Lysa Rector.
Coat color inheritance in the Doberman is relatively easy to predict. While there are actually 5 colors, there are only 3 sets of genes that determine color. Basic scientific nomenclature dictates that a capital letter is used to represent the dominant gene in a pair, and the lower case letter designates the recessive.
The first pair of genes we will discuss are the 2 most common, seen in all Dobes. They are the color genes, determining the basic, intrinsic color of the Dobe, either Black (B) or red (b). All Dobermans are either black or red, but color can be modified by the other 2 pairs of genes. If a Doberman has 2 Black genes (BB) it will be black. If it has 2 red genes (bb) it will be red. If it has one of each (Bb), it will be a red-factored black, which is a black capable of producing red. Every parent Doberman contributes either a black gene or a red gene to it’s offspring. BB animals always contribute a B gene, bb animals always contribute a b gene, and Bb animals contribute one or the other, with a 50% probability of each.
The second pair of genes we will discuss determine intensity of color. This pair of genes is called the dilution factor, seen in black Dobes as blue, and in red Dobes as fawn. Because dilution is a recessive trait, having the effect of lightening the color of blacks and reds, 2 of these recessive genes must be present in order to express visible influence. We will call the LACK of dilution D, and the presence of dilution d. A Doberman with DD will not show or be able to produce dilution. A Doberman with Dd will not show dilution - it will be black or red, but it will be able to produce dilution. A Doberman that is dd IS a dilute - a blue or a fawn. A Black Doberman with dd is a blue and a red Doberman with dd is a fawn.
Homozygous means that the 2 genes of the gene pair match, as in BB or bb. Heterozygous means there is one of each, ie, Bb, Dd.
Two more important terms are genotype and phenotype. The genotype is the Dobe’s genetic potential to express a particular trait, in this case color. The phenotype describes how the Dobe looks - in this case, Black, red, blue or fawn (or white - we will get to white in a minute.) There are 5 possible phenotypes. There are 27 possible genetypes, but we will only discuss nine right now.
Coat color inheritance in the Doberman is relatively easy to predict. While there are actually 5 colors, there are only 3 sets of genes that determine color. Basic scientific nomenclature dictates that a capital letter is used to represent the dominant gene in a pair, and the lower case letter designates the recessive.
The first pair of genes we will discuss are the 2 most common, seen in all Dobes. They are the color genes, determining the basic, intrinsic color of the Dobe, either Black (B) or red (b). All Dobermans are either black or red, but color can be modified by the other 2 pairs of genes. If a Doberman has 2 Black genes (BB) it will be black. If it has 2 red genes (bb) it will be red. If it has one of each (Bb), it will be a red-factored black, which is a black capable of producing red. Every parent Doberman contributes either a black gene or a red gene to it’s offspring. BB animals always contribute a B gene, bb animals always contribute a b gene, and Bb animals contribute one or the other, with a 50% probability of each.
The second pair of genes we will discuss determine intensity of color. This pair of genes is called the dilution factor, seen in black Dobes as blue, and in red Dobes as fawn. Because dilution is a recessive trait, having the effect of lightening the color of blacks and reds, 2 of these recessive genes must be present in order to express visible influence. We will call the LACK of dilution D, and the presence of dilution d. A Doberman with DD will not show or be able to produce dilution. A Doberman with Dd will not show dilution - it will be black or red, but it will be able to produce dilution. A Doberman that is dd IS a dilute - a blue or a fawn. A Black Doberman with dd is a blue and a red Doberman with dd is a fawn.
Homozygous means that the 2 genes of the gene pair match, as in BB or bb. Heterozygous means there is one of each, ie, Bb, Dd.
Two more important terms are genotype and phenotype. The genotype is the Dobe’s genetic potential to express a particular trait, in this case color. The phenotype describes how the Dobe looks - in this case, Black, red, blue or fawn (or white - we will get to white in a minute.) There are 5 possible phenotypes. There are 27 possible genetypes, but we will only discuss nine right now.
- The first is a Black Doberman that can only produce Black offspring. This Dobe’s genotype is BBDD. It is a DOUBLE HOMOZYGOUS (2 pairs of matching genes, ie BB, bb, DD, dd) dominant. This is referred to as a #1 Black.
- The second is a Black that can produce Black and blue offspring. It is a homozygous black that ‘carries’ a recessive dilution gene. (heterozygous - a non-matching pair of genes, ie - Bb, Dd) The genotype of this Dobe is BBDd. It is referred to as a #2 Black.
- The third is a Black that can produce Black and red offsrping - It is heterozygous (Bb) for color, and homozygous for intensity - in this case, DD - It can not produce dilution. This is called a #3 Black. It’s genotype is BbDD.
- The fourth is a double heterozygous. It is heterozygous for color Bb, and heterozygous for dilution Dd. It ‘carries’ both a ‘hidden’ red gene, and a ‘hidden’ gene for dilution. It is called a #4 Black, and it can produce black, red, blue and fawn. It’s genotype is BbDd.
- The fifth is a #5 blue. This is also a double homozygous. It is homozygous Black, BB, that is also homozygous for dilution, dd. It can produce blacks and blues only. The genotype is BBdd.
- The sixth is a #6 blue. This Dobe is heterozygous for color, Bb. It is homozygous for dilution, dd. It’s genotype is Bbdd and it can produce Blacks, reds, blues and fawns.
- The seventh is a #7 red. This Dobe is also a double homozygous - bb makes it red. DD means it can not produce dilution.
- The eigth is a #8 red. This red can produce dilution. It’s genotype is bbDd.
- The ninth is a #9 fawn. This is a double homozygous recessive. It contains 2 pairs of recessive genes. bb makes it red, and dd lightens the red, giving fawn.It is important to realize, that each parent contributes one gene FROM EACH PAIR to each of it’s offspring. Therefore, each parent contributes one gene for color and one for intensity of color to each pup.
But how do you get white???
OK. Here’s how. The white is a Recessive trait. A Dobe must have both genes in the pair to . show white. This pair of genes is a masking factor. What it does, is it hides the true color (and intensity of color) of the Dobe containing this pair of genes. Because it is a recessive, a Dobe that is white, has the homozygous gene pair ww. A Dobe that has the homozygous gene pair WW is not white, nor can it ever produce white. A Dobe with the gene pair Ww is white-factored. This means that it ‘carries’ the masking factor as a hidden recessive.
Numbers 1-9 listed above may or may not be WW, Ww orr ww. Each of the nine above genotypes have three possiblilities with respect to white. For example, a #1 Black, BBDD; A #1 black that is neither white, nor white factored has a genotype of BBDDWW - It is a triple homozygous dominant. A #1 Black that is white-factored has a genotype BBDDWw. A #1 Black that IS white, has a genotype BBDDww. This applies to all nine of the genotypes.
In review, the three pairs of genes determining the color (phenotype) of your Dobe are; 1.) The color genes, B and b. 2.) The intensity of color genes, D and d. 3.) The masking factor genes, W and w.
Each and every Dobe will have a pair of each genes that may be homozygous (matching pair) or heterozygous (mixed pair). If the genotypes of a pair of Dobes are known, the colors of their offspring can be predicted with accurancy. The important thing to remember, however, is that predicted and actually seen to happen as predicted are not always the same. For example, under normal circumstances, all offsping can be predicted to be 50% male and 50% female. However, a perfectly even split is rarely seen. Same thing with color. If you roll a six-sided dice 6 times, you are NOT LIKELY to roll each number once, although the probability of rolling any particular number is always 1 in 6.
Off Standard Doberman Color Information
Cream and/or White Doberman color...
The white Doberman is NOT a dilute nor is in the same genetic category. The gene responsible for the "white"/"cream" Doberman is SLC45A2 gene, which causes a recessive form of oculocutaneous albinism (OCA) . It is a deletion gene; it's missing genetic material on the chromosomes. One gene deletion is a carrier status and is not affected for OCA. Two gene deletions is positive for OCA. The D lotus is not a a deletion. Dilutes still express full coat color. SLC45A2 deletes a section of the gene and "deletes" the coding for the melanin/pigment turning the dog a variety from a diluted, dusty white to a bright snowy white. The white Doberman are genetically a standard color under the white.
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0092127
The white Doberman is NOT a dilute nor is in the same genetic category. The gene responsible for the "white"/"cream" Doberman is SLC45A2 gene, which causes a recessive form of oculocutaneous albinism (OCA) . It is a deletion gene; it's missing genetic material on the chromosomes. One gene deletion is a carrier status and is not affected for OCA. Two gene deletions is positive for OCA. The D lotus is not a a deletion. Dilutes still express full coat color. SLC45A2 deletes a section of the gene and "deletes" the coding for the melanin/pigment turning the dog a variety from a diluted, dusty white to a bright snowy white. The white Doberman are genetically a standard color under the white.
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0092127
Melanistic and/or Solid Doberman Color
Melanistic Doberman are not “rare”, rather they are just different genes at play. Melanism in Doberman is due to a genetic mutation. There are three potential causes of a "solid" Doberman;
The K & A Lotuses
Genetically, all dogs simplified have either a solid black coat pigment or red/brown coat pigment (phaeomelanin). A solid black is called eumelanin. "Whether a dog has a solid eumelanin (black) coat or a coat with red/tan markings (caused by phaeomelanin) depends almost entirely on the K locus. K consists of three alleles:
Genetically, all dogs simplified have either a solid black coat pigment or red/brown coat pigment (phaeomelanin). A solid black is called eumelanin. "Whether a dog has a solid eumelanin (black) coat or a coat with red/tan markings (caused by phaeomelanin) depends almost entirely on the K locus. K consists of three alleles:
Because black is dominant, a dog with even just one KB gene will be solid black. A dog with two ky genes (i.e. homozygous for ky) will be able to show tan markings. These tan markings are determined by another locus, A (ASIP). So basically, a genotype of ky/ky allows a dog to show whatever it has on the A locus. A Kb/ky or KB/KB dog may be genetically tan-pointed or sable on the A locus, but won't be able to show those markings because of its dominant black allele/s. Dominant black dominates the whole of the A locus, but it can be modified by other genes, such as liver, dilution, greying, and merle. All of these will alter the way a dominant black dog looks, but the one thing they cannot do is add phaeomelanin (red) to the coat. The only way phaeomelanin can be added to the coat of a dog with the dominant black gene is through the e gene (E locus) - recessive red. This turns a dominant black dog (or indeed, any dog) into a solid red dog with black nose pigment. ... Most black dogs have the dominant black gene, but there's also another, less common gene that can cause solid black too - recessive black (a on the A locus)." The A lotus consists of four alleles:
http://www.doggenetics.co.uk/black.htm
Fun Fact: Doberman are one of a few breeds that carry only the tan point allele on the A lotus. That means all Doberman are born genetically tan pointed - though this can be overridden by the K Dominant Black or E lotus Extreme Masking as the points are visible in sunlight.
http://www.doggenetics.co.uk/tan.html
Melanistic Doberman are not “rare”, rather they are just different genes at play. Melanism in Doberman is due to a genetic mutation. There are three potential causes of a "solid" Doberman;
- A Lotus - a/a Recessive Black
- K Lotus - a single KB/ky and KB/KB on the K locus produce a solid, Dominant Black
The K & A Lotuses
Genetically, all dogs simplified have either a solid black coat pigment or red/brown coat pigment (phaeomelanin). A solid black is called eumelanin. "Whether a dog has a solid eumelanin (black) coat or a coat with red/tan markings (caused by phaeomelanin) depends almost entirely on the K locus. K consists of three alleles:
- KB - dominant black (solid black, no red). Sometimes referred to as simply K.
- kbr - brindle (this is dealt with on the brindle page, but for now all we need to know is that it acts as a k allele, but just adds brindle on top of any red markings).
- ky - recessive non-black (will still have black nose pigment and may have black markings, but may also have red markings too). Sometimes referred to as simply k.
Genetically, all dogs simplified have either a solid black coat pigment or red/brown coat pigment (phaeomelanin). A solid black is called eumelanin. "Whether a dog has a solid eumelanin (black) coat or a coat with red/tan markings (caused by phaeomelanin) depends almost entirely on the K locus. K consists of three alleles:
- KB - dominant black (solid black, no red). Sometimes referred to as simply K.
- kbr - brindle (this is dealt with on the brindle page, but for now all we need to know is that it acts as a k allele, but just adds brindle on top of any red markings).
- ky - recessive non-black (will still have black nose pigment and may have black markings, but may also have red markings too). Sometimes referred to as simply k. ...
Because black is dominant, a dog with even just one KB gene will be solid black. A dog with two ky genes (i.e. homozygous for ky) will be able to show tan markings. These tan markings are determined by another locus, A (ASIP). So basically, a genotype of ky/ky allows a dog to show whatever it has on the A locus. A Kb/ky or KB/KB dog may be genetically tan-pointed or sable on the A locus, but won't be able to show those markings because of its dominant black allele/s. Dominant black dominates the whole of the A locus, but it can be modified by other genes, such as liver, dilution, greying, and merle. All of these will alter the way a dominant black dog looks, but the one thing they cannot do is add phaeomelanin (red) to the coat. The only way phaeomelanin can be added to the coat of a dog with the dominant black gene is through the e gene (E locus) - recessive red. This turns a dominant black dog (or indeed, any dog) into a solid red dog with black nose pigment. ... Most black dogs have the dominant black gene, but there's also another, less common gene that can cause solid black too - recessive black (a on the A locus)." The A lotus consists of four alleles:
- Ay - sable
- aw - agouti
- at - tan points
- a - recessive black
http://www.doggenetics.co.uk/black.htm
- https://mashable.com/2015/03/05/black-animals-melanism/
- https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0226136
- https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0006435
- https://www.ncbi.nlm.nih.gov/pubmed/19182816
- https://www.pawprintgenetics.com/products/tests/details/163/?breed=114
- https://www.nature.com/articles/ncprheum0989
- http://www.doggenetics.co.uk/tan
Fun Fact: Doberman are one of a few breeds that carry only the tan point allele on the A lotus. That means all Doberman are born genetically tan pointed - though this can be overridden by the K Dominant Black or E lotus Extreme Masking as the points are visible in sunlight.
http://www.doggenetics.co.uk/tan.html
Clear Red Doberman
The E locus is responsible for many coat variations we see. In Doberman the back, red, blue or fawn top coat has a tan pointed base (aka pointed markings). The e/e mutation turns off the top coat color and shows the base coat. This is called recessive red. The stag red, often called “clear red”, Doberman is genetically e/e on the E locus gene. These dogs are born with out any black in their coat. These dogs are not rare, nor breed standard. They're simply different genetics at play. The genes responsible for the black or red coat are "turned off" exposing the under coat which makes up the tan points.
These recessive red/clear red Doberman are variations seen in the coat spectrum. The recessive reds are throwbacks to the German Pinscher and Manchester Terriers used during the breed's creation. The DPCA doesn't condone the breeding of off-standard colors. They have retained some older genetics that should be considered for genetic diversity. Those dogs of standard color and good representation of the breed can be used to lower the COI in lines that are heavily inbred.
Merle Dobermans
Dobermans naturally have a variety of coat color variations; black, blue, red, and fawn all with tan points as well as albino, clear red, and melanistic. Dobermans do not come in brindle, merle, piebald, roan, ticking or spotting. Any Doberman with those colors has been crossed and bred back to pure Dobermans. Back bred dogs, depending on how many generations, can appear and behave like traditional pedigreed Dobermans. They will also pull 100% Doberman after so many generations. This is what we are doing in our kennel for genetic Diversity. We are using merle Great Danes, and Catahoula Leopard Dogs, to create the desired coat colors. All Merles were mixed and bred back pure after so many generations. It is important to know that double merles (a merle bred to a merle to create all merle puppies) can be fatal to puppies (lethal white syndrome, double merle syndrome) or may have significant health issues (deafness, blindness, sensory issues/limitations, congenital eye/ear malformations, shortened lifespan, temperament and behavioral issues).
Sable Dobermans
Sable Dobermans are born with heavy black in their coat that fades over time. Please see the photos below. To many unaware breeders are passing them off as clear reds and they are not. Dobermans are homozygous for tan points (AT/AT). Sable Dobermans are (AY/AT), This color was brought in from cross breeding.
A-Locus
(Fawn/Sable, Tricolor/Tan Points, Solid Black)Description: There have been four different alleles identified in a dog’s genes that signal the agouti coloration (this coloration can be exemplified as the coloration of the wild brown rabbit), also known as the A locus. If you’d like to learn more about the difference between an allele and a gene, click here. These alleles are Ay, aw, at, and a.
These alleles are dominant in a hierarchy. This means that Ay is more dominant than aw, aw is more dominant than at, and at is more dominant than a. For example, if a dog is Ay/at, the color associated with Ay will appear on the dog, rather than the color associated with at. However, this is all dependent on whether or not the dog carries the dominant black gene at the K locus or the recessive gene on the E locus. If a dog carries one or both of these genes, the A locus is muted and the agouti coloration will not appear on the dog. This is because both the K locus and the E locus are dominant over the A locus.
The agouti gene (A Locus) determines the base coat color in dogs that are ky/ky for dominant black. Dogs must be ky/ky in order to express any alleles on the A locus. The color of the dog can still be modified by other genes, such as by the B locus or D locus, however. For example, if a dog is b/b (recessive) for the B locus, they will still have areas that are pigmented as black. However, it will be modified to appear as a chocolate pigment.
However, if a dog’s A locus codes for the fawn coloration and the dog is b/b for the B locus, the fawn dog will have a chocolate nose. In contrast, a dog that is at/at will have a chocolate and tan coat, rather than black and tan. If a dog is n/n for the gene, that means that the dog is recessive for this gene and the typical colors associated with the pattern are not expressed. This is a generic term used to refer to the expression of any coat color.
The "Ay" AlleleThe Ay allele is the most dominant of all four alleles on the A locus. The Ay gene produces a range of coat colors like light fawn colors, darker red colors, or even sable. This variation of color is due to variances in the expression of this gene. Dogs that are ky/ky for the K locus and have one or two copies of the Ay allele will always express the Ay coat pattern. This is because the Ay allele is more dominant than the ky allele expression. It is important to note, however, that a dog can appear as fawn or sable and could also carry any other of the three alleles. These other alleles, however, would not be expressed, and a person wouldn’t be able to tell the dog had the ability to produce other traits based on looks.
This does not mean that the dog with a fawn coat (Ay) will always pass on a copy of the Ay allele or the coat color that the parent has. A dog that is Ay/aw, Ay/C, or Ay/a has a 50% chance of passing on the Ay allele and a 50% chance of passing on the other alleles. A dog that has two copies of the Ay allele will always pass on the Ay allele. As long as that dog is bred to another dog that is n/n (recessive) for the K locus, the dog will always produce fawn or sable pups.
The "aw" AlleleThe aw allele produces a color known as "wild sable." This coat coloration is sometimes called the "wild type," or in some breeds, "wild boar." With this coloration, the hairs switch pigmentation from a black color to a reddish or fawn color. This color is sometimes seen in German Shepherds and other shepherd breeds. It is recessive only to the Ay allele. This also means that it is dominant to the at and a alleles, and will be expressed before the at and a alleles. If a dog is n/n for the Ay allele (meaning this allele is not expressed), a dog with one or two copies of the aw allele will express the aw coloration. A dog that is n/n for Ay and has one copy of the aw allele can carry either the at or a allele and not express them. However, even though the at and a alleles do not appear as a trait on the coat, either allele can be passed to any offspring.
The "at" AlleleBoth the black-and-tan and tricolor phenotypes (expressed traits) are caused by the at allele. A tricolor dog is black-and-tan, with white. White is generally just an absence of color, rather than a pigment the dog expresses. For a dog to be black-and-tan or tricolor, he must be n/n for the dominant black gene (the K locus). This means that the K locus is not expressed, and the dog will not be black. Furthermore, the dog must have either two copies of the at allele, or have one copy of the at allele and one copy of the a allele. The dog must be n/n for both the ay and aw alleles in order for at to be expressed. This is because the Ay and aw alleles are dominant over at. A dog that is at/at will always pass on a copy of the at allele to any offspring. This does not ensure that the puppies will be black-and-tan. The coat color of the offspring also depends on the genotype of the other parent.
The "a" AlleleIf a dog is ky/ky on the K locus, the dog must be n/n for Ay, aw, and at in order for the dog to express the a/a coloration. A dog that is solid black with the recessive K locus must also have the recessive a/a allele in order to express the black coloration. It is important to make this distinction because a dog can also be solid black with kB/kB or kB/ky under the K locus. The A locus is not needed for this type of dog. Therefore, this type of black dog does not need the a/a coloration in order to express the black color. You can learn more about this type of dog by reading about the K locus or the B locus.
This is also the case for dogs that are bicolor and are negative for the K locus (ky/ky). This is generally the cause of a solid black German Shepherd. The a allele is sometimes referred to as the recessive black gene. Because this allele is the most recessive, for a dog to express this phenotype he must have two copies of the a allele and be n/n for Ay, aw, and at. A recessive black dog will always pass on the a allele to all offspring.
GenotypeCoat ColorHidden Color
Ay/Ay Fawn/Sable None
Ay/aw Fawn/SableWild Sable
Ay/at Fawn/SableTricolor/Tan Points
Ay/a Fawn/SableSolid Black/Bicolor
aw/aw Wild SableNone
aw/at Wild SableTricolor/Tan Points
aw/a Wild SableSolid Black/Bicolor
at/at Tricolor/Tan PointsNone
at/a Tricolor/Tan PointsSolid Black/Bicolor
a/a Solid Black/BicolorNone
In most dog breeds the Agouti gene is only visible if the dog does not carry the dominant black gene. The dog can still carry any of the agouti alleles. However, this effect is usually hidden by the dominant black gene.
above information sited from https://avian.animalgenetics.us/Canine/Canine-color/ALocus.asp
another good source on the subject http://www.doggenetics.co.uk/tan.html
A-Locus
(Fawn/Sable, Tricolor/Tan Points, Solid Black)Description: There have been four different alleles identified in a dog’s genes that signal the agouti coloration (this coloration can be exemplified as the coloration of the wild brown rabbit), also known as the A locus. If you’d like to learn more about the difference between an allele and a gene, click here. These alleles are Ay, aw, at, and a.
These alleles are dominant in a hierarchy. This means that Ay is more dominant than aw, aw is more dominant than at, and at is more dominant than a. For example, if a dog is Ay/at, the color associated with Ay will appear on the dog, rather than the color associated with at. However, this is all dependent on whether or not the dog carries the dominant black gene at the K locus or the recessive gene on the E locus. If a dog carries one or both of these genes, the A locus is muted and the agouti coloration will not appear on the dog. This is because both the K locus and the E locus are dominant over the A locus.
The agouti gene (A Locus) determines the base coat color in dogs that are ky/ky for dominant black. Dogs must be ky/ky in order to express any alleles on the A locus. The color of the dog can still be modified by other genes, such as by the B locus or D locus, however. For example, if a dog is b/b (recessive) for the B locus, they will still have areas that are pigmented as black. However, it will be modified to appear as a chocolate pigment.
However, if a dog’s A locus codes for the fawn coloration and the dog is b/b for the B locus, the fawn dog will have a chocolate nose. In contrast, a dog that is at/at will have a chocolate and tan coat, rather than black and tan. If a dog is n/n for the gene, that means that the dog is recessive for this gene and the typical colors associated with the pattern are not expressed. This is a generic term used to refer to the expression of any coat color.
The "Ay" AlleleThe Ay allele is the most dominant of all four alleles on the A locus. The Ay gene produces a range of coat colors like light fawn colors, darker red colors, or even sable. This variation of color is due to variances in the expression of this gene. Dogs that are ky/ky for the K locus and have one or two copies of the Ay allele will always express the Ay coat pattern. This is because the Ay allele is more dominant than the ky allele expression. It is important to note, however, that a dog can appear as fawn or sable and could also carry any other of the three alleles. These other alleles, however, would not be expressed, and a person wouldn’t be able to tell the dog had the ability to produce other traits based on looks.
This does not mean that the dog with a fawn coat (Ay) will always pass on a copy of the Ay allele or the coat color that the parent has. A dog that is Ay/aw, Ay/C, or Ay/a has a 50% chance of passing on the Ay allele and a 50% chance of passing on the other alleles. A dog that has two copies of the Ay allele will always pass on the Ay allele. As long as that dog is bred to another dog that is n/n (recessive) for the K locus, the dog will always produce fawn or sable pups.
The "aw" AlleleThe aw allele produces a color known as "wild sable." This coat coloration is sometimes called the "wild type," or in some breeds, "wild boar." With this coloration, the hairs switch pigmentation from a black color to a reddish or fawn color. This color is sometimes seen in German Shepherds and other shepherd breeds. It is recessive only to the Ay allele. This also means that it is dominant to the at and a alleles, and will be expressed before the at and a alleles. If a dog is n/n for the Ay allele (meaning this allele is not expressed), a dog with one or two copies of the aw allele will express the aw coloration. A dog that is n/n for Ay and has one copy of the aw allele can carry either the at or a allele and not express them. However, even though the at and a alleles do not appear as a trait on the coat, either allele can be passed to any offspring.
The "at" AlleleBoth the black-and-tan and tricolor phenotypes (expressed traits) are caused by the at allele. A tricolor dog is black-and-tan, with white. White is generally just an absence of color, rather than a pigment the dog expresses. For a dog to be black-and-tan or tricolor, he must be n/n for the dominant black gene (the K locus). This means that the K locus is not expressed, and the dog will not be black. Furthermore, the dog must have either two copies of the at allele, or have one copy of the at allele and one copy of the a allele. The dog must be n/n for both the ay and aw alleles in order for at to be expressed. This is because the Ay and aw alleles are dominant over at. A dog that is at/at will always pass on a copy of the at allele to any offspring. This does not ensure that the puppies will be black-and-tan. The coat color of the offspring also depends on the genotype of the other parent.
The "a" AlleleIf a dog is ky/ky on the K locus, the dog must be n/n for Ay, aw, and at in order for the dog to express the a/a coloration. A dog that is solid black with the recessive K locus must also have the recessive a/a allele in order to express the black coloration. It is important to make this distinction because a dog can also be solid black with kB/kB or kB/ky under the K locus. The A locus is not needed for this type of dog. Therefore, this type of black dog does not need the a/a coloration in order to express the black color. You can learn more about this type of dog by reading about the K locus or the B locus.
This is also the case for dogs that are bicolor and are negative for the K locus (ky/ky). This is generally the cause of a solid black German Shepherd. The a allele is sometimes referred to as the recessive black gene. Because this allele is the most recessive, for a dog to express this phenotype he must have two copies of the a allele and be n/n for Ay, aw, and at. A recessive black dog will always pass on the a allele to all offspring.
GenotypeCoat ColorHidden Color
Ay/Ay Fawn/Sable None
Ay/aw Fawn/SableWild Sable
Ay/at Fawn/SableTricolor/Tan Points
Ay/a Fawn/SableSolid Black/Bicolor
aw/aw Wild SableNone
aw/at Wild SableTricolor/Tan Points
aw/a Wild SableSolid Black/Bicolor
at/at Tricolor/Tan PointsNone
at/a Tricolor/Tan PointsSolid Black/Bicolor
a/a Solid Black/BicolorNone
In most dog breeds the Agouti gene is only visible if the dog does not carry the dominant black gene. The dog can still carry any of the agouti alleles. However, this effect is usually hidden by the dominant black gene.
above information sited from https://avian.animalgenetics.us/Canine/Canine-color/ALocus.asp
another good source on the subject http://www.doggenetics.co.uk/tan.html
Long Coat Dobermans
The long hair gene in Dobermans is a recessive trait passed down through generations from the start of the breed when they crossed in Gordon setter's for the purpose of improving the Dobermans coat color. These gene being recessive only pops up when two carriers are bred together. This information is stated in Philipp Gruenig's book The Doberman Pinscher - History and development of the breed.