Genetics- expression

[chemgrl08]

Hi all. I have a batch of eggs that are a cross between a golden albino female and a leucistic male. The eggs are developed to about 1 week and I can start to see eyes and such (which is pretty cool!) I noticed that it seems like a lot of them have black eyes though, and I had suspected that I would get some golden albinos from the pair. Either I am tricking myself because I'm only NOTICING the ones with black eyes (presumably leucistic) or perhaps the eyes develop differently after hatching? That wouldn't seem to make sense. Or is the pair supposed to give less than a 50% albino rate, as I had predicted?
Also, there is the off chance that the father is gfp. (I had previously purchased 2 leucistics, one with gfp, but unfortunately one of them died a while back.) I don't have a blacklight at home to check the father, so I don't know which one died (the gfp or the normal leucistic.) I was able to look at the eggs under a blacklight at my local university when they were around 2 days developed (I work in a chemistry lab. Perks of the job. ) I didn't see any gfp expression, but I wondered whether the gfp is expressed even as embryos, or if they need to develop more before it is expressed?
Thanks! This breeding is so interesting! Genetics, biology...

[monomike]

Here's my guess, (and it is just that). My guess is your leucistic salamander is a homozygote dominant fore this trait. (Your albino is homozygote recessive for melanin.) What this means is that the Leucistic donated its dominant gene for leucisim each time and the albino donated its recessive each time. My guess is all your young 'uns carry the gene for albinism, but as heterozygotes. If you breed one of them back against the Luecistic parent in a year or so, you will get the 50/50 you were hoping for.

I hope that helps!

[Kaysie]

Well, since leucism is a recessive trait, I don't think that's exactly accurate.

Here's how it works: you have a golden albino female and a leucistic male. Your female is a/a (albino), D/x (not leucistic [which makes white albinos]). Your male is A/x (not albino), and d/d (leucistic).

Using a punnet square, we can determine that you will get 50% A/a (not albino, but a carrier), and 50% a/x. We don't know what the X stands for until the offspring are developed. If you have no albino offspring, we know that your male is A/A, and not a carrier of albino (and all of your offspring are A/a, not albino but carriers). If you have 50% albino offspring, you know the male is A/a (a carrier).

As for what animals will be white: We know your female is not white (as it's a golden albino), so she's D/x. Your male is leucistic, so he's d/d. You can extrapolate the same calculations above to determine how many animals will be white (leucistic [A/x, d/d] or white albino [a/a, d/d]) and how many will be dark (either wild-type [A/x, D/x] or golden albino [a/a, D/x]).

GFP seems to be generally passed on as a simple dominant with varying expression. It should be visible in the egg, but maybe not in 2 day old embryos.

[chemgrl08]

Ah thank you, this is all very interesting. Although I have another development now: Some of the hatchlings (just hatched this morning!) and embryos are starting to acquire a blotchy green color, like a wild type. There IS a wild type female in the same tank; could I have mistakenly indicated the golden albino as parent? Ahhh so cool!!! I'm having a blast with this.

[Neil C]

What colour were the eggs when they we laid? I'm guessing white if the dark eyes were obvious. If they were white then your golden albino is the mum, if they were black then your wild type is the mother. The greenish patches you are seeing may result from the influence of the GFP.


Regards Neil

[chemgrl08]

Ah! That makes sense. Yes, they were white when they were laid; perhaps its a gfp father after all.Thanks everyone for sharing your knowledge!

[Kaysie]

Also, I don't know why I didn't mention this earlier: you can also get wildtypes out of this pairing!

If your female is a/a, D/D and your male is A/A, d/d, you will get all A/a, D/d offspring, which will be normal wildtypes.

[Neil C]

Wild types can theoretically appear in the young of any two axolots. All axolotls are descendants of wild types so all must carry some wildtype DNA.


Regards Neil

[Kaysie]

Barring genetic mutations, two albinos will never give you wildtypes. They just don't pass on those genes.

[Neil C]

As you can see I'm still learning :0)


Regards Neil

[melfly]

I have a Female Gold (parents unknown) and a Male Leucistic (parents both leucistic)
Their spawn is 100% wild, everytime.

She also lays 100% wild with my Wild type (parents not known)

She has Spawned once with a wild type (golden albino mother, leucistic father) and had 50/50 wild/gold....

Its interesting stuff

Mel