Colors
I have begun a study of how color is determined in the dog's coat. I am just learning
and want to share what I learn with you. I must give credit where it is due. The first
book that I read is: How To Breed Dogs by Leon R. Whitney, D.V.M. This book had some
basic information, but I wanted more. Everything that I read said that the ultimate
source was The Inheritance of Coat Color in Dogs by Clarence C. Little. I found a copy
on eBay. For being a little book (No pun intended), less than 200 pages, it is amazingly
expensive. Most of the information below comes from Little's book. Below is a picture
of some of my represented colors.
and want to share what I learn with you. I must give credit where it is due. The first
book that I read is: How To Breed Dogs by Leon R. Whitney, D.V.M. This book had some
basic information, but I wanted more. Everything that I read said that the ultimate
source was The Inheritance of Coat Color in Dogs by Clarence C. Little. I found a copy
on eBay. For being a little book (No pun intended), less than 200 pages, it is amazingly
expensive. Most of the information below comes from Little's book. Below is a picture
of some of my represented colors.
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Let's start with the basics: Genes are chemical combinations on chromosomes in cells that determine
characteristics of the animal, or plant for that matter. A puppy will get one gene for each
characteristic from each parent; thus they will have two genes for each characteristic. Chromosomes
are structures in the center of all cells. There are dominant genes and recessive genes. When a
gene is dominant, it only needs one copy to show, express itself. If a gene is recessive, it needs two
copies to express itself. The expression, what you see, is called the phenotype. The actual chemical,
gene makeup, is called the genotype. For example: You see two puppies that are black. Because the
gene for black in dogs is dominant you don't know what the genotype really is. One puppy could be
carrying blue or liver and you wouldn't know it, because these are recessive genes. Only the black
shows. Recessive genes can hide for many generations, until a dog is bred to another one that
carries the same recessive gene. Scientists have given the different color and pattern genes letters
to represent them. There is usually a subscript which I am unable to do with my keyboard, but bear
with me; I will try to represent them the best that I can. Dominant genes are represented by capital
letters, and recessive genes by small letters.
Let's start with A: The A genes determine the amount and distribution of dark color; such as black,
brown or tan. As, the s should be subscripted, allows the dark color to cover the entire dog. A solid
black dog would have As. To help you remember this, think of the s as meaning solid. The ay restricts
the dark color and can produce a completely tan dog when there are genes for black. Think of the y
as standing for yellow. The gene for tan points, or Dobie markings, is at. The t can stand for tan.
Since the As is dominant, the other A genes can hide behind it. A dog that has Dobie markings would
have to be at,at in order for it to show. If you breed a solid black dog to a Dobie marked dog, all of the
puppies will look black but have the genotype As,at. Sometimes when a puppy is young you can pick
up the hidden at as a slightly lighter color in the typically tan spots. Most of the time, you would not
know that they carried the at unless you were told. If you breed an As,at dog to another As,at dog
what would you get? The results are known as expected genetic ratios and are: 1/4 would be As,As;
1/4 would be at,at; 1/2 would be As,at. This does not mean that you would get this in every litter. This
is the ratio that would be expected over a number of litters. Thus, 1/4 would not carry the Dobie gene;
1/4 would be Dobies and 1/2 would be Dobie carriers. There are other possible A genes. The wild or
agouti gene is aw. This gene is believed to produce banding or tipping such as that seen in German
Shepherds. Some researchers have postulated another A gene that restricts the dark pigment to a
saddle on the back such as in beagles. This gene would be represented by as.
Now let's take a look at the B genes. These are the best understood and researched of the color
genes. They, also, are fairly straight forward. The gene for black is B. This gene is dominant over b
which is the liver gene. B for black, b for brown. Liver dogs have brown noses and green or copper
colored eyes. It takes only one B to make a dog black, but it takes two b's to make a dog a liver. What
makes a liver dog all the different shades are the modifier genes such as the A's above. A liver dog
with ay will be creme or yellow. A black dog with ay will be tan or yellow. A dog with the genotype B,b
is a liver carrier.
Let's tackle the C genes now. The C genes control the depth of color. The most common and
dominant is C. C is the gene for full color, pigmentation. This is what you see with a very deep black,
chocolate liver or rich mahogany red. The next gene is cch; the ch is the subscript. This gene is
called chinchilla. This gene has more effect on the red or yellow pigment than it does on black. It,
cch, reduces the amount of color that comes through. The third C gene is ca for complete albinism.
This would produce a white animal with pink eyes. This gene is extremely rare. The fourth C gene is
ce for extreme dilution. This gene washes out the color in both black and liver dogs. This is probably
what gives us those beautiful creme white livers.
The next genes for color that we will look at are the D genes. There are two different genes in this
group. The first and the dominant is D. This gene causes a density of pigment in both black and
brown. The second gene is d. This gene affects both black and brown and dilutes the color. D for
dense; d for dilute. This d gene causes the so called blues or can lighten the livers. There is a great
variation in its expression, meaning that you can get numerous shades of blues or livers. This d
needs two genes, one from each parent to be expressed or show. If a dog has just one, it is a carrier.
What you will see is the effect of D.
Well, here goes! Let us take a look at the E genes. These genes are by far the most complicated and
confusing of the color genes; therefore, I will take them in small bites. The most dominant at this site
is Em. This is the gene that causes black masks. It is even more dominant than E which causes
extreme or intense coloring. Of course, if you have a black dog with a black mask, B,B,Em,E, you can't
see it. You will know it when that dog produces puppies. This is true of our Alphy. He is Em,E. If a
dog carries the Em gene, nothing trumps it. Then there is the ebr for brindling. This gene, ebr, is less
dominant than E but more dominant than e. Alphy's gold brindled puppies are ay,ay,Em,ebr. I told you
that it was complicated! Don't worry! There will be no test. A dog with ebr,ebr will be brindled; but so
will a dog with ebr,e. The e gene blocks both black and brown. This is the gene that gives us reds
and yellows. The C genes are very important in the reds and yellows. A deep red like Irish Setters will
have the gene complement of e,e,C,C. A champagne gold like my Monroe is e,e,cch,cch. Remember,
the cch reduces pigment. Red livers are probably ay,ay,b,b,C,C,D,D,e,e. What else can I say?
Here are the genes at the G locus, site. There are two different genes at this site that affect color.
The dominant gene is G. This is the gene that leads to greying or silver. It is dominant over the g that
allows black to stay black. If you have a black dog with g,g then it will stay striking black. A dog with
G,g that is black will gradually turn grey as it matures. A dog that is born with G,G is usually a reddish
black and will turn to that beautiful silver like our John(Pictures below. If a dog is a silver, you can
usually see the change beginning at about six weeks of age.
S is for spotting. The S genes are very tricky, but I will try to explain them. There are four different S
genes. The capital S is for no spotting or solid and is dominant over the others. That is easy enough.
Next si is for Irish spotting. The i should be a subscript. Irish spotting is named that way because it
was first identified in an Irish rat. It is not really spotting at all but a regular pattern of white that
appears on the dog. Irish spotting is always very symmetrical, such as all white feet and a white tip on
the tail. Modifiers affect how much white appears. If there are minus (less color) modifiers, then
there is more white. Plus modifiers give more color. The perfect parti Shih Tzu with the white beard,
white blaze, white collar, white feet, white tail tip and solid color saddle would be from the Irish
spotting gene with minus modifiers. The si is dominant over sp and sw. The next spotting gene is the
pied, or parti, gene: sp. The sp gene gives a very irregular spotting pattern. It is affected in the same
way as the Irish gene by plus and minus modifiers. The sp is dominant over sw. The fourth spotting
gene is the sw for white. This is one of the ways that a dog can be white. If you see a dog with only
one spot or no spots and all white, it is probably because of the sw gene. The sw is also affected by
plus and minus modifiers. The other way to get white is with the C genes for complete dilution. One
more caveat: When you see a dog that is a solid color except for one or two spots on his/her chest
that is usually due to the combination S,sp. The S is incompletely dominant over the sp, and a little bit
of white breaks through. This pattern would be a clue that the dog carries the parti gene.
I hope that this helps some of you out. I am always open to questions or deeper explanations.
Contact Ruthie
characteristics of the animal, or plant for that matter. A puppy will get one gene for each
characteristic from each parent; thus they will have two genes for each characteristic. Chromosomes
are structures in the center of all cells. There are dominant genes and recessive genes. When a
gene is dominant, it only needs one copy to show, express itself. If a gene is recessive, it needs two
copies to express itself. The expression, what you see, is called the phenotype. The actual chemical,
gene makeup, is called the genotype. For example: You see two puppies that are black. Because the
gene for black in dogs is dominant you don't know what the genotype really is. One puppy could be
carrying blue or liver and you wouldn't know it, because these are recessive genes. Only the black
shows. Recessive genes can hide for many generations, until a dog is bred to another one that
carries the same recessive gene. Scientists have given the different color and pattern genes letters
to represent them. There is usually a subscript which I am unable to do with my keyboard, but bear
with me; I will try to represent them the best that I can. Dominant genes are represented by capital
letters, and recessive genes by small letters.
Let's start with A: The A genes determine the amount and distribution of dark color; such as black,
brown or tan. As, the s should be subscripted, allows the dark color to cover the entire dog. A solid
black dog would have As. To help you remember this, think of the s as meaning solid. The ay restricts
the dark color and can produce a completely tan dog when there are genes for black. Think of the y
as standing for yellow. The gene for tan points, or Dobie markings, is at. The t can stand for tan.
Since the As is dominant, the other A genes can hide behind it. A dog that has Dobie markings would
have to be at,at in order for it to show. If you breed a solid black dog to a Dobie marked dog, all of the
puppies will look black but have the genotype As,at. Sometimes when a puppy is young you can pick
up the hidden at as a slightly lighter color in the typically tan spots. Most of the time, you would not
know that they carried the at unless you were told. If you breed an As,at dog to another As,at dog
what would you get? The results are known as expected genetic ratios and are: 1/4 would be As,As;
1/4 would be at,at; 1/2 would be As,at. This does not mean that you would get this in every litter. This
is the ratio that would be expected over a number of litters. Thus, 1/4 would not carry the Dobie gene;
1/4 would be Dobies and 1/2 would be Dobie carriers. There are other possible A genes. The wild or
agouti gene is aw. This gene is believed to produce banding or tipping such as that seen in German
Shepherds. Some researchers have postulated another A gene that restricts the dark pigment to a
saddle on the back such as in beagles. This gene would be represented by as.
Now let's take a look at the B genes. These are the best understood and researched of the color
genes. They, also, are fairly straight forward. The gene for black is B. This gene is dominant over b
which is the liver gene. B for black, b for brown. Liver dogs have brown noses and green or copper
colored eyes. It takes only one B to make a dog black, but it takes two b's to make a dog a liver. What
makes a liver dog all the different shades are the modifier genes such as the A's above. A liver dog
with ay will be creme or yellow. A black dog with ay will be tan or yellow. A dog with the genotype B,b
is a liver carrier.
Let's tackle the C genes now. The C genes control the depth of color. The most common and
dominant is C. C is the gene for full color, pigmentation. This is what you see with a very deep black,
chocolate liver or rich mahogany red. The next gene is cch; the ch is the subscript. This gene is
called chinchilla. This gene has more effect on the red or yellow pigment than it does on black. It,
cch, reduces the amount of color that comes through. The third C gene is ca for complete albinism.
This would produce a white animal with pink eyes. This gene is extremely rare. The fourth C gene is
ce for extreme dilution. This gene washes out the color in both black and liver dogs. This is probably
what gives us those beautiful creme white livers.
The next genes for color that we will look at are the D genes. There are two different genes in this
group. The first and the dominant is D. This gene causes a density of pigment in both black and
brown. The second gene is d. This gene affects both black and brown and dilutes the color. D for
dense; d for dilute. This d gene causes the so called blues or can lighten the livers. There is a great
variation in its expression, meaning that you can get numerous shades of blues or livers. This d
needs two genes, one from each parent to be expressed or show. If a dog has just one, it is a carrier.
What you will see is the effect of D.
Well, here goes! Let us take a look at the E genes. These genes are by far the most complicated and
confusing of the color genes; therefore, I will take them in small bites. The most dominant at this site
is Em. This is the gene that causes black masks. It is even more dominant than E which causes
extreme or intense coloring. Of course, if you have a black dog with a black mask, B,B,Em,E, you can't
see it. You will know it when that dog produces puppies. This is true of our Alphy. He is Em,E. If a
dog carries the Em gene, nothing trumps it. Then there is the ebr for brindling. This gene, ebr, is less
dominant than E but more dominant than e. Alphy's gold brindled puppies are ay,ay,Em,ebr. I told you
that it was complicated! Don't worry! There will be no test. A dog with ebr,ebr will be brindled; but so
will a dog with ebr,e. The e gene blocks both black and brown. This is the gene that gives us reds
and yellows. The C genes are very important in the reds and yellows. A deep red like Irish Setters will
have the gene complement of e,e,C,C. A champagne gold like my Monroe is e,e,cch,cch. Remember,
the cch reduces pigment. Red livers are probably ay,ay,b,b,C,C,D,D,e,e. What else can I say?
Here are the genes at the G locus, site. There are two different genes at this site that affect color.
The dominant gene is G. This is the gene that leads to greying or silver. It is dominant over the g that
allows black to stay black. If you have a black dog with g,g then it will stay striking black. A dog with
G,g that is black will gradually turn grey as it matures. A dog that is born with G,G is usually a reddish
black and will turn to that beautiful silver like our John(Pictures below. If a dog is a silver, you can
usually see the change beginning at about six weeks of age.
S is for spotting. The S genes are very tricky, but I will try to explain them. There are four different S
genes. The capital S is for no spotting or solid and is dominant over the others. That is easy enough.
Next si is for Irish spotting. The i should be a subscript. Irish spotting is named that way because it
was first identified in an Irish rat. It is not really spotting at all but a regular pattern of white that
appears on the dog. Irish spotting is always very symmetrical, such as all white feet and a white tip on
the tail. Modifiers affect how much white appears. If there are minus (less color) modifiers, then
there is more white. Plus modifiers give more color. The perfect parti Shih Tzu with the white beard,
white blaze, white collar, white feet, white tail tip and solid color saddle would be from the Irish
spotting gene with minus modifiers. The si is dominant over sp and sw. The next spotting gene is the
pied, or parti, gene: sp. The sp gene gives a very irregular spotting pattern. It is affected in the same
way as the Irish gene by plus and minus modifiers. The sp is dominant over sw. The fourth spotting
gene is the sw for white. This is one of the ways that a dog can be white. If you see a dog with only
one spot or no spots and all white, it is probably because of the sw gene. The sw is also affected by
plus and minus modifiers. The other way to get white is with the C genes for complete dilution. One
more caveat: When you see a dog that is a solid color except for one or two spots on his/her chest
that is usually due to the combination S,sp. The S is incompletely dominant over the sp, and a little bit
of white breaks through. This pattern would be a clue that the dog carries the parti gene.
I hope that this helps some of you out. I am always open to questions or deeper explanations.
Contact Ruthie
| On the Left is John, one of our past silvers at 8 weeks. On the Right, John at 6 months. |
