Posted by:
DMong
at Mon Apr 30 12:04:09 2012 [ Email Message ] [ Show All Posts by DMong ]
There is all sorts of information on melanophores, tyrosinaise, xanthophores, and everything else pertaining to chromatophores (pigment cells) and the dynamics of how they operate, as well as what types are responsible for which colors and combinations. However, regarding the fairly new t-plus gene in the nelsoni you won't really find any specifics on. It hasn't been around long enough to know all the ins and outs of how it works just yet. But regardless of that, there is a lot of info on tyrosinaise positive animals, L-dopa testing, ad all sorts of other in-depth stuff.
Below is just one link to some of Bernard Bechtel's work that correlates precisely with many other things I have read about pigment cell dynamics in the past.
As to precisely WHEN something stops being one descriptive genetic term and begins being another one altogether is quite difficult for any hobbyist to know with any certainty. For instance, on a scale of 1 to 10, when exactly would what is "thought" to be common hypomelanism instantly become a "t-plus" albino by it's color?.....nobody really knows any of this, and there are countless variables with all of these mutations as well as countless types of different species in the hobby displaying VERY different visual looks that can even be the same type of genetic mutation only they could work with different amounts of certain proteins giving a totally different look. Just one example would be how does the other poster know (as he claims)that the extreme hypo Honduran gene is in fact "t-plus and not an extreme form of hypomelanism in my silvery/green colored extreme hypos????. Those aren't chacolatey/purple at all. What looks like one thing in one species/ssp. of snake can be very different in another type of snake. Hell, ALL snakes that have black pigment (melanin) are actually t-plus anyway because they all DO in fact contain tyrosinaise to synthesize amino acids/proteins into melanin. We merely call them "t-plus" to describe the look of the brownish/purple tyrosinaise that we see. Different strains and bloodlines of t-plus can prevent the cells from producing ANY melanin, or allow SOME to leach in and be synthesized, or allow large amounts to be synthesized. No person on earth can simply look at an animal and distinguish exactly what is going on, all a person can do without a laboratory is assume some educated guesses.
Also, I don't think extreme hypo Hondos are tyrosinaise positive albinos, but who knows. I have clutches of those that vary from 1 to 10 as well, so how do you really know what is going on in the pigment cells to label them as?..LOL!. It is not even CLOSE to being as simple as what some are saying..........not even close in my opinion. I still keep saying that "the more I find out, the less I actually "know".
Anyway, here is just that one link, but there is TONS of stuff on this all over the net if you google certain pertinent key words like I have. Also there is a bunch of stuff pertaining to xanthophores erythrophores, carotenoid retention, iridophores, and gobs of other stuff that again correlates with other information I've read. This info is great stuff, but know PRECISELY when it applies to any given mutation can be tricky at BEST sometimes. Some mutations are fairly simple to explain, but certain forms of hypo and t-plus will always leave us scratching our heads, especially when one understands enough to know it is extremely variable and hard to distinguish from other similar looking things. When you have read all this, you will be far less certain of many things you see labeled as whatever a hobbyist wants to slap on the deli cup label, that's for darn sure...
The actual mode of inheritence in the "t-plus" nelsoni may in fact be just like the ultra/ultramel gene in "corn" hybrids. arrrgh, here we go again..LOL!!!
Anyway, I wish I could be so certain of a lot of this like some seem to be..
~Doug
dynamics of tyrosinaise and other stuff
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"a snake in the grass is a GOOD thing" 
serpentinespecialties.webs.com
"some are just born to troll and roll"
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RE: t-positive / extreme hypo discussion - DMong, Mon Apr 30 12:04:09 2012