>It would stand to believe all boa albinos seem to be T positive because they have the ability to produce red and yellow coloration.

In mammals this would be correct. But fish, herps, and many birds have red and yellow pigments that are not melanin. They are pyridine compounds, if I remember correctly. Corn snakes have been tested and fround to be tyrosinase negative. They lack the black coloration caused by melanin but still have their red, non-melanin pigment.

Paul Hollander

*** I would have to agree with you Paul as far as the above statement goes although I assume you meant amelanistic corn snakes when you refered to corn snakes above. The ability to produce reds and yellows in reptiles is not an indication of a T Positive albino. Reds and yellows are synthesized within the Xanthophores by pteridine and carotenoid pigments (not tyrosinase) while melanin is synthesized in the melanophores and requires tyrosinase. (2 different chromatophores doing 2 different jobs in the production of color in reptiles) I also wanted to clarify a "T Positive Albino" is not just an animal that has active tyrosinase but an animal with active tyrosinase that is unable (for a variety of reasons) to synthesize Tyrosinase through the DOPA - Dopaquinone chemical reactions or oxidations to produce melanin within the melanosomes.
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Tom Burke
www.BurkeReptiles.com

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