Metamorphed Axy...

[Tim S]

Has anyone considered that some of the metomorphing Axolotls that have been reported may be mutations. Neoteny in Ambystoma mexicanum is controlled by a single recessive gene. So, a single mutation back to the ancestral gene (for metamorphosis) will cause the Axolotl to metamorphose.

[Kaysie]

Do you have a paper on this? I'd be really interested in reading it!

As far as mutations, amphibians are fairly plastic as far as phenotypical variations, so I don't know why this would be any different.

[slowfoot]

Originally Posted by Tim S

Has anyone considered that some of the metomorphing Axolotls that have been reported may be mutations. Neoteny in Ambystoma mexicanum is controlled by a single recessive gene. So, a single mutation back to the ancestral gene (for metamorphosis) will cause the Axolotl to metamorphose.

I believe it's more complicated than that. I actually worked (as an undergraduate) in the lab where most of this research was done. Without re-reading all of the literature and as far as I can remember, when they originally did the experiment, they crossed lab stock A. mexicanum with A. tigrinum. The ratios of paedomorphic individuals among the offspring of such crosses indicated that a single gene might be involved. Here's a ref for the paper if you want to look it up:

Voss, S.R. & H.B. Shaffer. 1997. Adaptive evolution via a major gene effect: Paedomorphosis in the Mexican axolotl. Proceedings of the National Academy of Sciences of the United States, 94(25): 14185-14189.

However, when they later did crosses using wild caught A. mexicanum and A. tigrinum, the offspring ratios indicated that more than one gene was controlling metamorphosis. I think that's all detailed here:

Voss, S.R. & J.J. Smith. 2005. Evolution of salamander life cycles: A major-effect quantitative trait locus contributes to discrete and continuous variation for metamorphic timing. Genetics, 170(1): 275-281.

Anyway, they explained the discrepancy as probably being the result of strong selection against paedomorphic individuals in laboratory strains. Animals that undergo spontaneous metamorphosis are generally destroyed and certainly aren’t being used as breeding stock for the available lines. In natural populations, it’s a more complicated story, but in the lab strain axolotl it could be a single gene mutation that leads to metamorphosis. However, I think it's much more likely that environmental factors are the cause of most of these cases.

If anyone can’t access the papers, just send me a pm and I’ll try to get you a PDF

[Tim S]

I should clarify that the spontaneous external/cryptic metamorphosis seen in some domestic Ambystoma mexicanum may be caused by a single gene mutation. This is based on earlier studies on A. tigrinum X A. mexicanum hybrids and their offspring (Humphrey, 1967. J. Hered. 58:95-100; Tompkins, 1978. Amer. Zool. 18:313-319).

By no means did I wish to imply that complete external and internal/physiological metamorphosis was controlled by a single gene in A. mexicanum or any other Ambystomid.

[bob2143]

Mate beautiful salamander was there a lot of change in his habits when he turned into a salamander, apart from walking on land.

[reptileman134]

Sweet axolotl morph. I haven't seen that before. I have heard of it, but have never seen pictures of it.

And to top it off it looks cool too!!

[TicTacJunkie]

Awesome!

what a pretty little fella, morphed axies are truly fascinating. thanks for sharing those!

[Axyloverxx]

Wow lo is gorgeous!!!!!!!

[slimer]

i think they look better with gills

[Tim S]

How about in gold?

[Shadow]

Wow Tim, is it yours? Very nice!

[Greatwtehunter]

It is so unnatural to see them morphed like that, that it looks fake. None the less its still pretty neat to see.

Later,
Justin

[Tim S]

Originally Posted by Shadow

Wow Tim, is it yours? Very nice!

He was. The last picture was taken in 1997. He lived a few more years after that.

[andymarchiando]

verry cool!!!!!

[BellaCornuta]

It's truly amazing how they do this. The fact that they stay adorable even after changing is my favorite part about it! Beautiful axie.

[BellaCornuta]

Are all axolotls in captivity crossed with A. Tigrinum?

[Gismonikon]

Think so-Humphreys are very common and often inbreed in axolotl
and with much tigrinum genom inside % quantity of morphed Axos is growing-
in all colours-

[Darkmaverick]

Thank you Gismonikon for sharing those fantastic pictures. It is most interesting to see the array of colours in morphed axies.

Regards.

[b00f]

they are ALL AMAZING!

some are really freaky, like the white one, it looks like it has no eyes