C: Albino (say what???)
updated February 3, 2015
Yes, technically C is called the Albino locus. The word "albino" doesn't start with C. And there's no such thing as an albino gerbil. But don't get confused yet!
C is where we find Chinchilla or Colourpoint genes. Either of those would be a better name as at least they start with C.
Gerbils have 3 genes here. If c existed in gerbils, then we'd have 4 C genes and have albino gerbils. But it doesn't so we don't. Instead we have a dominant C that's normal. And 2 genes that do some lightening work without being as extreme as c would be (if it existed).
c(chm) and c(h) are pretty similar. c(chm) lightens things up a bit, but c(h) is able to lighten more. It's like bleach, in a way. Gene is a janitor today, laundering gerbils. He has to be careful with the temperature though.
We'll start with what these genes do on gerbils with black eyes, P-.
gerbils with black eyes
colourpoint - c(chm)c(chm)
So let's toss in 2 small bottles of c(chm) bleach into the machine and add a black gerbil (let's pretend we did anyway - no gerbils were harmed during the writing of this page!). That gives us burmese. Here's Marvel as a very young pup, freshly bleached. It's not that he's so light; he's kind of brown, actually. c(chm) doesn't do all that much.
So Marvel grew and molted, but it turns out the effect of c(chm)c(chm) bleach wears off if it isn't kept warm enough. And his tail, nose, ears and feet aren't quite warm enough. So the original black colour becomes more visible on those cold places, the "points".
When c(chm) and c(chm) are together, the colour is called colourpoint. Burmese is colourpoint black. With most other colours we just call them colourpoint and the colour: CP nutmeg, CP agouti, and so on.
You might sometimes see this gene referred to as c(b) or cb. That's because the effect of this gene makes black gerbils look like burmese cats. So it was named b for burmese. Later the gene was studied more carefully, and it turned out it's not the same gene that makes burmese cats. So the name of the gene was changed to make it more accurate: chinchilla medium. The name of the gerbil colour, burmese, stayed the same. (Chinchilla medium would be a dorky name for a gerbil colour.)
light colourpoint - c(chm)c(h)
So, starting with a black gerbil again, Gene uses a bottle of c(chm) AND one of c(h) as well. We get a siamese gerbil.
c(h) bleach is a lot stronger than c(chm). Gazette shows off the fresh bleaching job on at 4 1/2 weeks of age. He's pretty light overall with a darker tail, though there is quite a bit of variability between pups.
Again, the lightening effect wears off if it isn't kept warm enough. And gerbil tails, ears, noses and feet are not warm enough.
The colourpoint genes also lighten the eyes slightly, but not enough that we can't still call them black. Bright lights can give them a reddish glow.
When c(chm) and c(h) are together, it's called light colourpoint (abbreviated LCP). c(chm) and c(h) on a black gerbil is actually light colourpoint black. But we call it siamese because they look like siamese cats.
When c(chm) and c(h) are together on a golden agouti gerbil, we get LCP agouti.
It doesn't look much like golden agouti any more! The ticking gets really light. The tail stays pretty dark though, because it's cooler than the body.
white gerbils with pink eyes
DTW (Dark-tailed white aka Himalayan) - c(h)c(h) P-
Now it gets interesting.
This time it makes no difference if we start with a black gerbil, an agouti gerbil, or pretty much anything else with black eyes. Use 2 bottles of strong c(h) bleach and we get... a white gerbil with pink eyes! You can see the completely white tails on the 10 day old white pups. Then you see the adult DTW with dark tail.
The colour of the tail can vary quite a lot depending on what other genes are hanging around. c(h) has a very strong lightening effect, so much that the whole body bleaches to white. It can take several months before any colour starts to show up on the tail. Only the tail is cool enough to get some colour. The other points are too warm for such strong bleach.
Here's Pallas at 4 weeks, showing off his bright pink eyes. According to his genes, his eyes are black. But c(h)c(h) bleaches them to pink.
PEW (Pink-eyed white) - c(-)c(-) pp
Now before anyone thinks I'm making this too simple, here is some math:
In other words, you can mix and match any recessive c genes with pp and your gerbils will all be white with pink eyes. And stay that way. No other genes make any difference at all. White Paper will look just the same no matter which group of genes she has.
A- c(chm)c(chm) pp is just as PEW as aa c(h)c(h) pp. PEW, PEW and PEW.
the single c(chm) or c(h)
black eyes - P-
Here's a black gerbil, Rally, and Gene may or may not have used a bottle of either c(chm) OR c(h) bleach in the washer load.
What happened? Well, not much.
One dose of c(chm) or c(h) doesn't do anything with P-. It looks much like CC with P-.
pink eyes - pp
Most of the time, one recessive gene doesn't do a lot. But if the gerbil is pp, then it's different. A single c(chm) or c(h) makes a whole new colour.
A- CC pp: argente golden A- Cc(chm) pp: topaz A- Cc(h) pp: argente cream
aa CC pp: lilac aa Cc(chm) pp: sapphire aa Cc(h) pp: dove
We'll show a couple of examples. Argente cream is quite a bit lighter than argente. Sapphire is somewhat lighter than lilac, though in this case there are white markings involved, making Star lighter than a solid sapphire... which brings us to our next gene, Sp, white spotting.