Is Chinchilla Dominant?

[JDB Rabbitry]

Wondering if the chinchilla gene is dominant or not? I've gotten mixed answers online.

 

[judymac]

The answer is: yes and no. Chinchilla is on the 'C' color gene. There are five options on that gene (called allelles), in descending order of dominance. Most dominant is full color C, which includes all the 'normal' colors like chestnut agouti, lynx, opal, cinnamon (chocolate agouti), tortoiseshell, orange/red/fawn, orange/fawn harlequin. There are two different version of the pigment melanin that make up all rabbit colors. The dark colors are formed from eumelanin, and the yellowish shades from pheomelanin. With the full color allele, both pigment factories are geared up and ready to go into full production of whatever color the rabbit's other genes calls for. Not the all colors need both pigments, self black, blue, chocolate and lilac only use the dark pigment eumelanin, but both pigment factories are open for business if needed.

Next down is chinchilla, coded c(chd). The small 'c' in the front shows that it is recessive to another allele on this gene (in this case, the full color C), and 'chd' is short for chinchilla--dark. In this option, only the dark pigment factory is fully operational, the yellow pigments are only slightly available (like in bronzed chinchilla kits) or not open at all. So, a genetic chestnut agouti that has the chinchilla c(chd) instead of full color C, will not have the yellowish shades. The outer chestnut will just be gray, and the middle fawn agouti band on the hairshaft will be pearl white instead of yellowish--a chinchilla is really just a chestnut agouti with the chinchilla allele.

Think of some of the other full color patterns:

• Tortoiseshell is orange/fawn/red body with dark points. Replace full color C with chinchilla, and you get pearly white on the main body, with the same dark points. Some breeds call this color 'pearl'.
• Orange/red/fawn agouti has yellowish shades extended all the way to the end of the hairshaft. Chinchilla removes yellow, so you're left with a pearly white rabbit all over, but with dark eyes, not blue or red/pink like BEW or REW albino rabbits. If the rabbit would have been a nice clean, clear orange agouti, it will be all pearl white. If it would have had a little dark smut on the fiber tips, you'll still have those dark tips, the classic ermine color, which is what this color becomes when you add chinchilla + orange agouti--also called frosty.
• The self colors black/blue/chocolate/lilac: Okay, here's one that can really mask itself, because there is no yellow pigment involved. So, you could have a self colored rabbit + chinchilla, that still looks like a full-color self, when in reality it is a self chin. One clue could be eyes that are blue or blue-gray instead of the correct full color brown, but a self chin could also have brown eyes, so it's not a foolproof clue.
• Orange/black harlequin (or orange/chocolate, fawn/blue or fawn/lilac): Here the agouti colors normally all on one hairshaft get moved to patches of the skin instead. Where a normal harlequin would have the dark pigment patches interspersed with fawn/orange patches, when you add chinchilla you get pearl white patches instead of fawn--what we call a magpie.

There are three more options on the C gene, chinchilla is dominant over all three:

1. Sable, coded c(chl) for chinchilla--light. Here, the yellow factory is still closed down, but even the dark pigments are not at full capacity--black becomes dark sepia brown.
2. Pointed White/Californian/Himalayan, coded c(h) for Himalayan. Here the main body color pigment factories are totally closed, the yellow pigments are closed, and the dark pigments only show on the points (ears, nose, feet, tail).
3. Albino ruby-eyed white (REW), coded with just a small c because it is the most recessive option. Here, the rabbit could be any color at all genetically, but all the pigment factories are totally closed, and they cannot produce any color.

The options on the C gene can be incompletely dominant. That means that a rabbit that has a mix of a dominant allele and a recessive one, could have the recessive allele do something sneaky to make its presence known. For example, a chestnut agouti rabbit with both a dominant full color C and a recessive chinchilla allele, could still end up with blue or gray-blue eyes, and make it unshowable, which is why many breeders keep their chinchilla lines separate from their full color lines.

 

[Dimplz]

Wondering if the chinchilla gene is dominant or not? I've gotten mixed answers online.

Depends on the chinchila gene.

Chinchilla dark c(chd) is recessive to full color, but dominant to chinchilla light c(chl). The order of dominance on the color loci are 1.full color, 2.chin dark, 3.chin light, 4.himi, and 5.albino. So chin dark is only recessive to full color. Chin light is recessive only to full color and chin dark.

The chin dark gene removes ALL yellow pigment. Leaving monotones of black and white.

The chin light gene removes MOST, but not all of the yellow pigment. Resulting in shades of black that look brown.

Examples would be:

American Chinchilla = A_B_c(chd)_D_E
Black ticking and ear lacing, with a pearl internediate band. Slate under color on top and on the belly. White agouti markings. Eyes usually brown; blue-gray or sometimes marbled.

Sable Chinchilla = A_B_c(chl)D_E
Sepia base and tip color, white intermediate band. Points noticably darker according to sable shading. Eyes brown with a ruby glow in correct lighting.

This is probably why you got mixed answers. There are two recognized chinchilla genes. Dark is dominant to light.