Origin of Albino Axolotls

E

edward

Guest
I was going through a book I just picked up (Amphibian Biology vol 1, 1994) when I ran across a note describing the origin of the albino gene in axolotls. It was introduced by crossing axolotls with an albino tiger salamander (for the reference on the procedure see Humphry, R.R. 1967, Albino axolotls from an albino tiger salamander through hybridization. J. Hered. 58: 251-256)). The process was apparently not a simple one as it required rescueing hybrid embryos by nuclear transplantation, gonadal grafts and only resulted in 6 animals that were potential hybrids.



Ed
 
Wouldn't mind seeing that Ed. Malacinski's book reads as if it was spontaneous mating.

Due to all the cross mating and the basis of lab animals in setting up colonies I would suggest that it would be very difficult now to get an axie without the albino genes from animals bred in captivity.
 
Hi Mik,
I would like to see it too. The reference on the procedure is from the bibliography for those who want to go look it up. Unfortunately work doesn't get the Journal of Heredity (I'm lucky we get Copeia). The comment on the procedure is an almost exact quote from the book.

Ed
 
so...does this mean that albino axies are like the american chestnut - in so much as they are not really the actual species but a really diluted hybrid? if the albino genes are interwoven in all axies then is it that they also are not true 'axolotls'?.
 
In short, I would suspect that the majority of axolotls in captivity today carry some A. tigrinum genes (protiens).

Ed
 
I think it's a little more detailed than that. Off the type of my head I think that's how the gold albino came up. Their are a few different lines of white albinos that I don't think involved tiger salamanders. Of course off the top of my head I don't think true Ambystoma mexicanum will come on land naturally. Others say different.
 
I think it's possible that we're wandering into purist territory here.

In some breeds of dogs years ago when the gene pool was quite small it wasn't uncommon to have a mating with another breed to fix a percieved problem. The next mating would be back with animals of the breed you were interested in.
Obviously the offspring are half'n'half and subsequent generations the proportion of out-bred genes is diminshed. After several generations no one would dispute the breed of the animal you were in inspecting. Clearly from pedigree records it carries an outcross mating but visually and for all intents and purposes after several generations what remains is 'pure-bred'.

Axies might have been mated with A.Tigrinum over a century ago. But after a 100 years (100 generations or more) who could clearly dispute that they aren't A.mexicanum? You could claim pure blood for those in the wild certainly but most pets and lab specimens must be contaminated with A.Tig genes. Given that they were nearly the same in the first instance much of their genetic make-up must be identical.

Isn't it also possible that animals in wild may have inter bred with similar species at one time?

It makes me think what other materiel has been retained apart from the albino genes? Things that aren't as noticeable.
 
If tiger salamanders could have fertile young with axolotls then doesn't that kind of make them the same species?
 
no
 
Why not? It's the typical text book answer for what makes a seperate species. Two animals of seperate species can not produce fertile young (except in freak occasions like that mule in Morocco), It even says so in the natural history museum. I guess science changes all the time though.
 
benjamin -they are different species-but can hybridize and were once probably the same species, sometimes hybrids arent fertile (like mules)-but since they are so similar-this is not the issue here.
mikki,
dogs are a way different situation - they are all the same specie -all dog breeds are different 'races' but not different animals. the dog related parallel is like breeding a wolf to a domestic dog -you will get offspring (dogs long ago were bred from wolves)-but these offspring are not the same specie. this is why i brought up the issue of the american chestnut -the actual chestnut from our east was wiped out by a fungus(i think it was a fungus) that they were introduced to but couldnt fend off. there was a program introduced that hybridized a foreign chestnut tree (not the same specie) that had resistance to the fungus. they have been out breeding the hybrids with more american chestnut genes (they must have a stash of seeds somewhere)-the idea is to keep the disease resistance in the genetic make up while making the hybrids as close to the american chestnut as possible.the point is however-that the american chestnut is essentially extinct due to its vulnerability to foreign disease. so to have a hybrid is to not have the same animal. the process of diluting the genes can however make the animal as close to the original as possible-but -like the chestnut hybrid-it may have some different traits from the diluted foreign genes. since axies can occasionally morph and tigers remain neotenic, i would wonder if those with albino genes have a higher occurrence of morphing naturally.
 
I agree with you Paris, but I wasn't arguing different breeds being different species I was trying to demonstrate the gene dilutuion aspect.

I think your chestnut tale does it better but I was also trying to say that other alleles/genes and traits are possibly inherited along with the albino genes. Perhaos there is some gene there for morphing or switching morphing on or off. Perhaps it requires a combo of 3 or 4 alleles to make it happen. I dunno way beyond me but fascinating all the same.
 
Well can't genetically predisposed axolotls morph at any time in development (some morph before sexual maturity, others morph after.) If it is different alleles then maybe then different combinations could lead to morphing at a different stage in the life cycle, just like different combinations of colour genes decide what type of albino an axo is.
 
Hi Mike,
It didn't specify which "albino" type was the result.
Hi Ben,
The rule of thumb is not that they cannot interbreed but that they normally do not. There are numerous examples of fertile hybrids between different species such as lions and tigers, corn and king snakes (jungle corns). Just look at the ads on kingsnake sometime. As long as the chromosomal numbers are correct then the animals are fertile (this is why mules are normally not fertile as donkeys and horses have different chromosomal numbers).

Paris, there isn't a need for a stash of nuts as the trees are killed but resprout from the trunk and the shoots often get big enough to flower before the tree is killed again (only to resprout). In this case over time I would expect the tigrinum genes to be diluted not the axolotl genes as the animal being selected for was an axolotl.

Ben,
Metamorphosis is triggered hormonally. I would suspect that it is possible to block this on multiple levels changing the required triggers.

Ed
 
Ed,

On the types of albino:
Golden albino D/? a/a results in a relative excess of xanthophores resulting in gold colour

White melanoid D/? a/a m/m obviously the a/a cancels out/overides the m/m and leaves a white axie

White axanthic D/? a/a ax/ax similar action to the melanoid example

White axanthic melanoid D/? a/a ax/ax m/m what can I say.

Question: axanthic axies are reported to die bfore reaching sexual maturity. Do you know if this is true of axanthic albinos (ax/ax and ax/ax m/m).

Question: The golden albino only requires the a/a combo to become reality whereas the white albino is typically a/a m/m. My casual observations (Peter Scott remarks that goldens will be popular one day in his book) are that until recently the white albino was the more common. I find this quite odd as it requires 2 sets of alleles to be in the correct configuration rather than just one. So unless there was a proliferation of recessive m type alleles in a population the golden should be the more common. Would this not suggest that the first white axies were probably the result of the first hybrids and from stock that had M/m or m/m as a common combo?

Don't get me started on leucistic albinos (d/d a/a)...lol

I am waiting delivery of a couple of papers I discovered on axie genetics and hope to learn more soon.
 
Hi Mikki,
I have not heard that there was a lethal recessive gene attached to axanthism in axolotls.

As amphibians have several layers in the skin causing color pigment there are several types of albinism depending on which layer (layers) of pigment producing cells are affected (this can also be seen in some reptiles). This causes different colored animals before we get to white (or pigmentless) animals. (Blue greentree frogs are an example of a animal that is albino for yellow pigments).
I would suspect that under the old common definition of albino (white or pigmentless) that the white axolotl was the result (but I could be very wrong and defer to those with more information.) If someone has access to the Journal of Heredity article I cited above I suspect this would answer the question as I would expect a description of the resulting albinos to be present in the paper.

Ed
 
Yeah I have read that the different colours are porduced by the various colour pigments in different skin layers. But my readings indicate that the alleles operate directly on the colour pigment cells not the layer.

I produced a table in this forum called colour genetics. Ed please take a look. All this info comes from reading Malacinkski's and Scotts books. Plus a few web sources.
 
A little further on in the text it indicates that white axolotls were obtained from the wild and from numerous strains maintained in the labs (does not distinguish between leucistic and albino). An axanthic mutant was described in 1971 and was the product of repeated genetic crosses and spontaneous mutations.

Ed
 
Hey Mikki,
I forgot to ask, do you have a link to the table?

Ed
 
sure its in this forum sub topic. Just go back up one level and scroll down about 10 threads to AXOLOTL COLOURS VS GENOTYPE.
 
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