Reptile & Amphibian Forums

Going by what I read here:
"Tyrosinase (tie-ROW-sin-ace) is the major enzyme involved in the formation of melanin pigment. Tyrosinase is responsible for converting tyrosine to DOPA and on to dopaquinone (dopa-QUIN-own). The dopaquinone then forms black-brown eumelanin or red-yellow pheomelanin. The tyrosinase enzyme is made by the tyrosinase gene on chromosome 11, and alterations (also called mutations) of this gene can produce one type of albinism because the tyrosinase enzyme made by the altered gene does not work correctly."

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

Quote taken from: http://albinism.med.umn.edu/newfacts.htm#whatis
The link that Tom Burke posted below.

You have to continue reading but what they refer to as putting the "hair" bulb in a chemical solution (DOPA) is proving or disproving the presence of Tyrosinase. If no Tyrosinase is present, even though the chemical solution provides the necessary DOPA for the production of melanin......no melanin will be formed indicatimg a T negative form of albinism. It basically is proving the absence of tyrosinase in the test subject by artificially providing the neccessary Dopa. If tyrosinase is present but unable to mix in the test subject, when put with the chemical solution (DOPA).......melanin will form indicating a T positive form of albinism.

Here is the section this came from:

How do we classify Oculocutaneous Albinism?
The classification of OCA has changed a great deal over the years, with much of the work coming from the International Albinism Center and the help of all of the wonderful individuals and families who have helped with these studies. For many years, the term "albinism" referred only to people who had white hair, white skin, and blue eyes. Individuals who had OCA and pigmented hair and eyes were identified, particularly in the African and African-American population, and terms such as 'incomplete albinism', 'partial albinism' or 'imperfect albinism' were used for this, but these terms are inappropriate and are no longer used. In the 1960's, Dr. Carl Witkop developed the hairbulb incubation test to separate pigmenting and non-pigmenting types of OCA and started to use the terms "ty-neg" or "tyrosinase-negative" and "ty-pos" or "tyrosinase-positive" OCA. Freshly plucked hairbulbs from a person with OCA were placed in a solution of tyrosine or dopa (see Pathway above) in a test tube and watched to see if pigment formed in the pigment cells in the hairbulb. If no pigment formed, the test was negative and the diagnosis was ty-neg OCA. If pigment formed in the hairbulb, the test was positive and the diagnosis was ty-pos OCA. Although this simple test showed that there were different types of OCA, subsequent studies have shown that the hairbulb incubation test is not very sensitive and has many false negative and false positive responses. As a result, the hairbulb incubation test is no longer used in the evaluation of an individual with OCA.

Burke Reptiles

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Tom Burke
www.BurkeReptiles.com

All this T pos T Neg is it or isn't it. Very interesting ,Technical ! But in practical application what does it all add up to ? Answers to trivia questions.

I understand that in today's sophisticated reptile market it's important to be able to explain why your animals are special using terminology that combines high school biology with the finesse of a lawyer and the slickness of used car salesmen. But in reality morph breeding is nothing more then putting this color snake in with that color and playing lets see what comes out. Like in school when you were small .

The water colors . You mixed your yellow with the blue and got green. Did it matter if you understood how each color in Munsell Color Tree system is represented by a distinct position on the tree.The Hue color value is represented by placement on the circumference, saturation by the horizontal distance of the color from the central axis, and brightness by the vertical position on the trunk. You just mixed your paint and put a little yard in front of the house. But this has a greater significance. We're talking Boa morphs and being able to validate the magic Albino word seems to be of great importance. But why ?

If ultimately a team of microbiological atom splitting technicians with a hundred degrees on the wall and no snakes determines thru a series of test so advanced that Dr Frankenstein himself would be amazed .That yes believe it or not these are albinos . What would change ? The animals would look, breed and act the same . The only thing that would change would be now you can say for sure that no matter how they may look they really are albinos and not some crappy type 2 hypo. Bottom line it's still the same snake by any name. I guess if staying busy doing all this advanced " Genetic Research " helps to keep kids off the street it does serve some purpose.

Ernie Eison

n/p
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Chris & Alliey
www.bloodyleopard.com
E-mail Us

But I can accept how you feel. It's all a matter of how far you want to take your hobby. I don't think there's anything wrong with what you've said but I'm sure there are some people that would like to know how the proverbial house is built in the hopes they can better build their own in the future. I for one have never been a fan of just putting things together haphazardly. I've always asked questions and researched what I could in the hopes of becoming better at what I do not only in reptile breeding but in other aspects of my life. I think my kids call it OCD!! LOL Selective breeding and the results that are possible are the satisfactions I feel in this hobby and it's what helps me get through all the snake and rat poooo!!!
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Tom Burke
www.BurkeReptiles.com

>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

>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

that should have been amelanistic corn snake rather than just corn snake. Good catch.

Paul Hollander