"It's been my impression that "hypo" is not really a specific mutation, rather sort of a catch all term to describe any number of genetic conditions that result in reduced melanin. Whereas "T Plus" describes a specific mutation that results from a specific process.



In other words "hypo" describes a result and "T Plus" decribes a cause. All "T Plus Amelanistics" are hypo because they look hypo and hypo is just a look, but not all hypos are T Plus Amels because hypo is just a look that can result from numerous different causes"





Well, I agree with parts of that, and don't with other parts.



Since the term hypomelanism quite literally means....pertaining to reduced melanin (dark pigment), it is basically describing a visual look (phenotype)of reduced melanin, not the actual cause or dynamics of the pigment cell's malfunction as you mentioned.



I will also point out that ALL snakes with any dark pigment are "tyrosinaise positive. This simply means the cells in the animal's melanophores(dark pigment cells) do in fact contain tyrosinaise. By the very same token, the term "tyrosinaise positive"(t-plus)in regards to the albino forms simply means that tyrosinaise (the melainin pre-cursor enzyme) is indeed present within the melanophores, but for many different unknown reasons the cells will not allow it to mix normally with the other proteins needed to produce melanin within the melanocyte itself. This term describes the purplish/lavender color we see in certain "t-plus" animals when it is there all by itself unable to synthesize ANY melanin at all. However, different strains and mutations of this in all sorts of different snakes in the hobby can and do often allow varying amounts of tyrosinaise to be synthesized into varying amounts of melanin, and THIS is where the confusion lies with the terms hypo and T-plus, and what to call these certain phenotypes in the hobby.



Also, many t-plus animals are not "amelanistics" because they casn synthesize some degree of melanin. The term "amelanistic" is more accurately reserved specifically for animals that express a complete and total LACK of melanin, not a reduction (as in hypomelanism) or a form of t-plus where some tyrosines are able to be synthesized into dark pigment. The prefix "a" in front of "melanistic" means pertaining to NO melanin whatsoever.



Anyway, both hypomelanism or tyrosinaise positive can be extremely tough to discern or diferentiate from each other in certain snakes, because BOTH can display substantial variation depending on a great number of things going on within the pigment cells. Also, other underlying colors where the melanin would normally be can be a huge factor in how a certain type of snake will look as well.



I guess what I am getting at here is that almost nothing to do with animals is as cut-and-dry as many hobbyists think..







cheers, ~Doug
-----
"a snake in the grass is a GOOD thing"



serpentinespecialties.webs.com





"some are just born to troll and roll"

[ Show Entire Thread ]