Reptile & Amphibian Forums

ok, I can't find a genentics forum so I'll ask here.
I've got eggs from two double hets - albino and hypo, which would be AaHh.
As I see it the chances out of 16 would be:
aa 1
Aa 2
hh 1
Ha 2
HA 2
Ah 2
AA 1
HH1
Hh 2
ah 2

Am I correct in assuming that Aa would be albino, Ha would be hypo het albino, hh would be het hypo? HA is, of course, what I'm most interested in seeing.

Thanks in advance for KNOWLEDGEABLE responses.

JH

AB Ab aB ab
---------------------------------
AB AABB AABb AaBB AaBb

Ab AABb AAbb AaBb Aabb

aB AaBB AaBb aaBB aaBb

ab AaBb Aabb aaBb aabb!!!

AABB 6.25%
AABa 12.5%
AAbb 6.25%
AaBB 12.5%
AaBb 25.0%
Aabb 12.5%
aaBB 6.25%
aaBb 12.5%
aabb 6.25%

Good Luck!

Tom Anderson

Thanks, Tom. I'm as lost as ever. If things go on schedule the eggs should hatch on the 29th, I'll let you know what comes out of the 12 eggs.
Of course, I have no idea what the AABB would look like so I might not even realize I've got one.

JH

That's right - you'll only know if you have a aaBa, aaBB, Aabb, AAbb, or aabb (hypo and albino). I'll describe the notation more clearly. You are dealing with two separate and independent genes so you can look at it like two separate conditions like this:

AA is normal looking and NOT het for albino
Aa is normal looking and het for albimism
aa is an albino looking
BB is normal looking and not het for hypo
Bb is normal looking animal and het for hypo
and bb is hypo looking animal

The percentages represent a statistical results expected when breeding a double het to a double het. If you add up the albino looking animals, there's an 18.75% chance a snake will look like an albino, and 18.75% chance it will look like a hypo and a 6.25% chance it will be both hypo and albino. The rest will look normal, but will may be hets either of hypo, albino, or both.

AA BB 6.25% totally normal animal = het for nothing
AA Ba 12.5% Normal looking - just het for hypo
AA bb 6.25% hypo looking and NOT het for albino
Aa BB 12.5% Normal looking - just het for albino
Aa Bb 25.0% Normal looking - double het (what your breeders are)
Aa bb 12.5% hypo looking and het for albino
aa BB 6.25% albino looking and NOT het for hypo
aa Bb 12.5% albino looking and het for hypo
aa bb 6.25% true albino and hypo animal (This is what your shooting for)

Here's a Punnett square calculator.
http://www.changbioscience.com/genetics/punnett.html

N/P

Lance

San Diego Gophers

While on the genetics subject, I have an easy question. Is it true that if you had albino x albino, ALL of the offspring would albino?

n/p

If both parents are carrying ONLY the amel trait, then yes, amel x amel= all amels.

However, if the parents are carrying hidden traits, then you might get more. Say both are Amel het hypo, then you WILL get all amels, some het for hypo, some not and then possibly one or more that are both amel and hypo.

Am I correct, because I am definitely not an expert?

Yes and no. First let's assume we're only talking about simple recessive traits. I don't know if there are any codominate albinism genes in snakes.

If you look at the albino trait independently then the answer the the question is yes, albino x albino = all albino. If it's also het for a bunch of other stuff, then all bets are off, but it will still be albino... just might be albino and hypo like JH's potential offspring, for example.

>>Yes and no. First let's assume we're only talking about simple recessive traits. I don't know if there are any codominate albinism genes in snakes.
>>
>>If you look at the albino trait independently then the answer the the question is yes, albino x albino = all albino. If it's also het for a bunch of other stuff, then all bets are off, but it will still be albino... just might be albino and hypo like JH's potential offspring, for example.

That last sentence is scary,,,,very scary. LOL

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Steve W.

Again, I am by far no expert, just trying to learn here. I agree with what you wrote as it is basically what I was saying, BUT let's try this scenario. Albino het aner x Albino het aner= All albinos, but some are het for aner and some are not and a few are possibly both albino and aner resulting in a different looking snake altogether (snow right?)

Snow is when you display both amelanistic and anerytheristic traits, just like ghost is when you display both hypomelanistic and anerytheristic.

If you want to see the endless variety of names for color and pattern morphs as they are combined just take a look at a ball python or cornsnake price list as an example these days. I have convinced myself that some people do these combos just to make up a new name??

Lance

ONE MORE THING TO CONFUSE YOU ALL:

Albinism in snakes occurs because the snake lacks the ability to produce melanin... The tricky thing is that this disorder can happen in more than one way on more than one locus.

It is possible to breed two albino animals together and get all normal animals. If the male is "broken" on one part of the chromosome and the female is "broken" on another their respective dominant genes will mask the disorder in the F1 generation. Those offspring will be normal double hets for two different types of albinism that occur independently.

FUN EH?

DAN
(The Alterna Documentary Guy)

Thanks, you just confused the hell out of me! I thought I had it all figured out. Although the case you explain is probably extremely unlikely I'm assuming.

Are you talking about two different genes that both independently contribute to albinism? Then it would be two just like simple recessive traits, right?

Tom

I have heard of it happening with 2 seperate albino lines, it was a long time ago.. I think in Cal kings? But anyway to produce an albino with a simple recessive (the normal amelanistic) you need that same gene contributed by both parents. If they each provide a diffetent method (gene) to produce the same effect you can get all normal looking offspring that are double hets (one for each method of amelanistic).

Genetics is fun like that...

correct.

correct. Like anery A and anery b. Two recessives that produce a similar outcome.

DAN

... But pretty uncommon. There are T and T- albinos in quite a few groups of snakes that I know of, and other simple recessives too.

For example: In the cornsnake you have Anery A and Anery B. Two genes different loci (spell?) that produce a corn without red.

I'm not saying it's common, I'm just saying that if the reason the question was posed was that someone had bred an albino to an albino and produced all normals, there is an explanation.

Thanks for all who read that.

DAN

Dan,

Thanks for the response. Are you aware of any Lampropeltis that have two simple recessive genes that contibute the same trait, ie. lack of melanin?

Thanks,
Tom

Not off the top of my head, but I believe in an earlier post a fellow said something about cal kings. The one's that I can remember are ratsnakes. This also happens in other organisms with an bunch of outcomes. I believe it is called complementation or something like that. It's been about 5 years since my 800 level genetics class. I think I got a D anyway.

dAN

n/p

I just remember it happened to a popular herp some time ago... Mentally filed it as "interesting" and have not retrieved that file in a very long time... had to blow some dust off of it.

Could have been corns? I am sure that somebody remembers better than me on this.

Lance

Okay, I did a quick search on webcrawler and I came up with complementation in like ten species. Seems to be more common in Boids. Retics, burms, balls, nicaraguans, but also ratsnakes (obsoleta)

I'm sure if you used google you could find even more.

DAN

I've got eggs from two double hets - albino and hypo, which would be AaHh.

This is what is called a dihybrid cross (two double hets bred to each other for two independent dominant/recessive loci).

Of course, you could produce 12 double recessive or 12 normals from you clutch of 12. The Punnett squares only give you the probabilities.

>>As I see it the chances out of 16 would be:
>>aa 1
>>Aa 2
>>hh 1
>>Ha 2
>>HA 2
>>Ah 2
>>AA 1
>>HH1
>>Hh 2
>>ah 2
>>
>>Am I correct in assuming that Aa would be albino, Ha would be hypo het albino, hh would be het hypo? HA is, of course, what I'm most interested in seeing.

The problem with your approach is that each snake gets two alleles at each locus.

Thus endeth the late night genetics lecture - class dismissed -
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Chris Harrison
San Antonio, Texas