Bunnylady
Herd Master
No, albinos don't lack color genes, they simply have genes at one location that say "no coat color pigment produced." They have to have something at every single location within their genetic code. You can't have nothing at a location, that is a major genetic no-no and usually isn't survivable. Most of the diseases caused by bad genetics are because of a faulty gene or an extra gene, not because of the lack of one.mama24 said:
Every rabbit has the potential to produce 2 pigments, phaeomelanin (the yellow/red pigment) and eumelanin (the black/brown pigment). He has a bunch of different genes that dictate just how much of each pigment he produces, and exactly where in his coat the pigment appears. It is the combined efforts of all of these genes that determines what color he is.
The A series decides the pattern, whether Agouti, Tan, or Self. The A series affects where in the hair coat the colors appear.
The B series determines the shape of the Eumelanin granule within the hair, making it appear either Black or brown (chocolate).
The C series influences the amount of pigment produced. There are several genes in the C series:
C - the most dominant, codes for the maximum amount of both pigments that the genes at the other locations allow
cchd - the chinchilla gene. Takes almost all of the yellow out, and a little of the black
cchm- (some people don't believe this one exists, but it's called the medium chinchilla gene)
cchl - the light chinchilla gene, also called the shaded gene. Removes all red/yellow, and a bit more of the black than the other two chinchilla genes. The reduced amount of black pigment looks brown, but this should not be confused with the effect of the chocolate (b) gene. This gene turns what would otherwise be a black self into a Siamese Sable.
ch - the Himilayan gene. This is very close to an albino, having red eyes, but areas of the body that tend to be cooler (ears, nose, tail, paws) will produce dark pigment. Himis will show dark pigment in the coat on other parts of their bodies, if the skin there got cooled when the hair was actively growing.
c - the Ruby-eyed White gene. This is the true albino, producing neither phaeomelanin nor eumelanin.
The D series determines how much of both pigments are produced, and causes the pigment granules within the hairs to clump together, allowing more light to pass through. This creates either a full colored(D) or a diluted effect (d), turning what would otherwise be a black rabbit into a blue, for example.
The E series affects where in the hair shaft the black pigment appears. The normal extension gene(E) allows it to appear anywhere the genes at other locations allow it to be; the non-extention gene(e) pushes it almost entirely out of the hair shaft, except in areas where shorter hair allow what little black pigment is left to appear more concentrated. This gene turns what would otherwise have been a black self into a Tort. Harlequin (ej) and steel (Es) occur in this series.
The Broken series. The broken gene (En) is dominant, and codes for the broken pattern. It requires the assistance of a lot of helper genes, called modifiers; they determine just what the broken pattern looks like on a particular rabbit. A rabbit can have as little as white on the feet, chest, and maybe a spot on the forehead ("booted") to almost entirely white with just a little color around the eyes (Hotot), depending on the modifiers present.
There are other series, too, but the above are the principal ones and the ones you are likeliest to be working with. Every rabbit has 2 genes from the A series, 2 from the B, and so forth. They may be two of the same kind, or maybe two different ones, depending on what it got from its parents. With a REW, you know that the rabbit has 2 copies of c in the C series, but it also has 2 somethings in the A series, 2 from the B series, etc, you just can't see what the others are because those 2 c's shut down the pigment production.
Here's an example: I had a REW Holland Lop doe that I bred to a Smoke Pearl buck. For the first couple of litters, I got Smoke Pearl and REW babies, which told me that he had a REW gene too (I kinda knew that already, actually)
In their 3rd litter, I had a Broken Smoke Pearl baby. Now, Broken is a dominant gene, if it's there you're gonna see it, and that buck was solid. If he had the broken gene (En) I'd have seen it, as he was solid, he must have 2 "solid" genes (en) in that series. So where did the broken come from? Well, the REW's sire was a broken, so it wasn't too hard to figure out. The REW doe had a broken (En) gene, you just couldn't see it because the REW genes had shut down the pigment production. REW's can be real wild cards in a color breeding program, because just looking at them, you have no idea what the other color genes they are carrying may be.
