Color Genetics
This web segment is intended to be an introduction to color genetics for the species we raise. I find it fun to play with color and guess at the colors of babies before the parents have even been bred! More importantly, I find it critical to consider color in my breeding decisions -- especially to avoid combinations that potentially result in unshowable/undesirable colors. However, in making decisions about breeding color should never be the only factor! A whole host of other genetic factors should also be considered in making decisions about which animals to breed (or not) and which to pair. Health, conformation, and even personality can all have a genetic basis. Most of those factors are far more important than color. Everything about an animal, from its bone structure to its fur, and even a lot of personality, is controlled by its genes. Most of these traits are controlled by really complicated polygenic (multiple genes controlling each trait) systems. But basic coat color is relatively simple controlled by just a few few genes which interact in well understood and predictable way to produce the colors we see. Basics -- DNA, found in every cell in every living thing on Earth, forms the 'codebook' for producing proteins, the building blocks of life. The DNA is organized into sections called called genes - each gene produces one protein. In all higher forms of life (not bacteria) genes come in pairs. In sexually reproducing animals (including rabbits, cavies, goats and chickens) each animal gets one gene from its mother and one from its father. In most cases, the genes are identical - all rabbits have all the genes for two eyes, two ears, 4 legs, etc - in other words, they have all the genes that make them rabbits. The interesting part comes in when the genes aren't identical -- all the wonderful variation we see is due to those small differences in the genes!
The coat colors in the mammals included here all come from variations in just two color proteins -- eumelanin and phaeomelanin. Some genes control production of these two proteins -- does the animal make them or not? Other genes control the pattern of color -- which portions of the animal have eumelanin and which have phaeomelanin? Yet other genes control subtle variations within the protein structure -- is the eumelanin black or brown? And yet others control the amount of the protein made -- is the color intense or dilute? These handful of genes work together on just these two proteins to produce hundreds, if not thousands, of colors and patterns.
All three of the mammals included here - rabbits, guinea pigs and goats share these common gene 'loci' (a loci is a location on the DNA, coding for a specific protein which does a specific job): A (pattern gene), B (eumelanin type gene), and E (extension gene). They also all have a 'gene system' referred to as 'rufus factor' which controls the phaeomelanin type. All three species also have several different loci that cause white spots -- all these genes work in similar ways -- they make a protein that inactivates (either randomly or in a specific pattern) the ability to produce the eumelanin and phaeomelanin. Rabbits have a C loci that has many variations (alternative genes) which can affect the production of both eumelanin and phaeomelanin. The most common of these variations is the gene which causes a true albino -- a white rabbit with pink eyes due to total lack of pigments caused by having two copies of the c gene. Guinea pigs also have this same loci, though not the same variations at it - for example, although guinea pigs can be white with pink eyes, they cannot be true albinos because they never have the c gene. Goats also don't have true genetic albinos -- variation at the c loci has never been described for goats (though blue-eyed whites are sometimes called albinos, it's a totally different gene). Rabbits have an alternative dilution gene d which has been describe for many other mammals (including mice and cats). Variations in the D loci have only recently been reported for guinea pigs (blue cavies are a deep navy shade tentatively assigned as dd, though the gene hasn't yet been sequenced) and has never been reported for goats. Guinea pigs have two alternative 'dilution genes' at a loci called P which works quite differently from D. Variations in the P loci have been described for rabbits (lutino) but have never been described for goats.
One interesting, but universal note on the A gene. In rabbits, the A gene is considered to be simple dominant while in the cavies it is described as partially dominant and in goats as co-dominant. The co-dominant rule for goats, while more complicated, actually works for all three species. Basically, if your A-loci gene pair tell you two different things -- one gene tells you to make eumelanin and the other to make phaeomelanin -- the only thing present at that part of the coat is the phaeomelanin. This is counterintuitive as in most cases eumelanin is darker (e.g. black) than the phaeomelanin (e.g., tan) and we intuitively think that the darker color should be the one we see.
Mom's Genetics Page is actually divided into a series of pages -- hopefully that makes it easier on you, the reader, than scrolling through everything to get to the part you want!
The coat colors in the mammals included here all come from variations in just two color proteins -- eumelanin and phaeomelanin. Some genes control production of these two proteins -- does the animal make them or not? Other genes control the pattern of color -- which portions of the animal have eumelanin and which have phaeomelanin? Yet other genes control subtle variations within the protein structure -- is the eumelanin black or brown? And yet others control the amount of the protein made -- is the color intense or dilute? These handful of genes work together on just these two proteins to produce hundreds, if not thousands, of colors and patterns.
All three of the mammals included here - rabbits, guinea pigs and goats share these common gene 'loci' (a loci is a location on the DNA, coding for a specific protein which does a specific job): A (pattern gene), B (eumelanin type gene), and E (extension gene). They also all have a 'gene system' referred to as 'rufus factor' which controls the phaeomelanin type. All three species also have several different loci that cause white spots -- all these genes work in similar ways -- they make a protein that inactivates (either randomly or in a specific pattern) the ability to produce the eumelanin and phaeomelanin. Rabbits have a C loci that has many variations (alternative genes) which can affect the production of both eumelanin and phaeomelanin. The most common of these variations is the gene which causes a true albino -- a white rabbit with pink eyes due to total lack of pigments caused by having two copies of the c gene. Guinea pigs also have this same loci, though not the same variations at it - for example, although guinea pigs can be white with pink eyes, they cannot be true albinos because they never have the c gene. Goats also don't have true genetic albinos -- variation at the c loci has never been described for goats (though blue-eyed whites are sometimes called albinos, it's a totally different gene). Rabbits have an alternative dilution gene d which has been describe for many other mammals (including mice and cats). Variations in the D loci have only recently been reported for guinea pigs (blue cavies are a deep navy shade tentatively assigned as dd, though the gene hasn't yet been sequenced) and has never been reported for goats. Guinea pigs have two alternative 'dilution genes' at a loci called P which works quite differently from D. Variations in the P loci have been described for rabbits (lutino) but have never been described for goats.
One interesting, but universal note on the A gene. In rabbits, the A gene is considered to be simple dominant while in the cavies it is described as partially dominant and in goats as co-dominant. The co-dominant rule for goats, while more complicated, actually works for all three species. Basically, if your A-loci gene pair tell you two different things -- one gene tells you to make eumelanin and the other to make phaeomelanin -- the only thing present at that part of the coat is the phaeomelanin. This is counterintuitive as in most cases eumelanin is darker (e.g. black) than the phaeomelanin (e.g., tan) and we intuitively think that the darker color should be the one we see.
Mom's Genetics Page is actually divided into a series of pages -- hopefully that makes it easier on you, the reader, than scrolling through everything to get to the part you want!
Rabbit Color Genetics
Section 1 "Colors in Our Rabbitry" Has the color genotypes for all the rabbits we have owned since we started breeding. This is mainly so anyone who has bought a rabbit from us can look up the color genes in our lines and see what colors their rabbit might be carrying. We tell you when you buy a rabbit from us, of course, and much of the information you can figure out from the pedigree, but sometimes we learn more about our lines based on later kits produced.
Section 2 "Rabbit Color Genetics 101" includes basic information on how the 5 main color genes (plus a few important extras) work. I developed this content as I was trying to teach myself rabbit color genetics - hopefully by sharing what I've found I can make it easier for the next learner!
Section 3 "Rabbit Color Genetics Chart" I developed this chart starting from a similar one on the NJWRC. I've expanded it to include the color names for all 4 of the breeds we work with - and a lot of the names for the unshowable colors as well. This is my cheatsheet that I find indispensable when I'm working on genetics problems.
Section 4 "Rabbit Color Genetics 102" Some examples - based on our real rabbits - of how to use color and genetic information in reading pedigrees, predicting kit colors and planning breeding.
Section 5 "Rabbit Colors Across Breeds" Each breed decides what to call colors somewhat independently ... resulting in considerable confusion. This section attempts to match genotypes and color names across breeds.
Section 2 "Rabbit Color Genetics 101" includes basic information on how the 5 main color genes (plus a few important extras) work. I developed this content as I was trying to teach myself rabbit color genetics - hopefully by sharing what I've found I can make it easier for the next learner!
Section 3 "Rabbit Color Genetics Chart" I developed this chart starting from a similar one on the NJWRC. I've expanded it to include the color names for all 4 of the breeds we work with - and a lot of the names for the unshowable colors as well. This is my cheatsheet that I find indispensable when I'm working on genetics problems.
Section 4 "Rabbit Color Genetics 102" Some examples - based on our real rabbits - of how to use color and genetic information in reading pedigrees, predicting kit colors and planning breeding.
Section 5 "Rabbit Colors Across Breeds" Each breed decides what to call colors somewhat independently ... resulting in considerable confusion. This section attempts to match genotypes and color names across breeds.
Cavy Coat and Color Genetics
Section 1 "Colors in Our Caviary" Has the color genotypes for all the cavies we have owned since we started breeding. This is mainly so anyone who has bought a cavy from us can look up the color genes in our lines and see what colors their cavy might be carrying. We tell you when you buy a cavy from us, of course, and much of the information you can figure out from the pedigree, but sometimes we learn more about our lines based on later pups produced.
Section 2 "Cavy Genetics 101" includes basic information on the genetics of the breeds followed by the genetics of the colors. The colors section is written with the assumption that the reader already knows the basic terms and something about rabbit color genetics. I developed this content as I was trying to teach myself cavy color genetics - hopefully by sharing what I've found I can make it easier for the next learner! Note that all names of breeds and varieties (colors) are based on the American Cavy Breeders Association Standard. This differs substantially from the names used elsewhere in the world!
Section 3 "Cavy Color Genetics Chart" I developed this chart based on the similar one for rabbits. This is my cheatsheet that I find indispensable when I'm working on genetics problems. Where I know them, I include the alternative names used in the literature from Britain and Europe.
Section 4 "Cavy Color Genetics 102" 101 flipped to give the most common, less preferred, and DQ'ed genotypes for the ~26 ACBA accepted colors along with a primer on figuring out genotype from phenotype.
Section 2 "Cavy Genetics 101" includes basic information on the genetics of the breeds followed by the genetics of the colors. The colors section is written with the assumption that the reader already knows the basic terms and something about rabbit color genetics. I developed this content as I was trying to teach myself cavy color genetics - hopefully by sharing what I've found I can make it easier for the next learner! Note that all names of breeds and varieties (colors) are based on the American Cavy Breeders Association Standard. This differs substantially from the names used elsewhere in the world!
Section 3 "Cavy Color Genetics Chart" I developed this chart based on the similar one for rabbits. This is my cheatsheet that I find indispensable when I'm working on genetics problems. Where I know them, I include the alternative names used in the literature from Britain and Europe.
Section 4 "Cavy Color Genetics 102" 101 flipped to give the most common, less preferred, and DQ'ed genotypes for the ~26 ACBA accepted colors along with a primer on figuring out genotype from phenotype.
Goat Color Genetics
Section 1 "Goat Color Genetics 101" Includes everything I've been able to find on Goat Color and Pattern genetics.
Section 2 "Goat Color Genetics 102" Playing with goat color genetics with some examples from our real herd.
Section 2 "Goat Color Genetics 102" Playing with goat color genetics with some examples from our real herd.
Wyandotte Chicken Color Genetics
Section 1 "Wyandotte Chicken Color Genetics 101" The basic chicken color genes in Wyandottes.
Peafowl Color and Pattern Genetics
Section 1 - Peafowl Genetics