# Other Pythons > Blood Pythons >  What is the difference between the T- and the T+ albino?

## EverEvolvingExotics

I have seen a bunch of ads for both, the T+ costs soooo much less than the T- albino.  Both are beautiful.  Can someone share comparison pics or descriptions for both?

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## llovelace

Don't know if this will help, but I found this

Making melanin (black) pigment starts with the amino acid tyrosine. It goes through a dozen or so chemical changes before becoming melanin. Tyrosinase is the enzyme that catalyses the first two chemical changes. One gene carries the information for making tyrosinase. If the gene changes enough, the resulting enzyme can't do its job, and no melanin gets made. The changed gene has become a tyrosinase-negative albino mutant gene. 

Some animals lack melanin but have normal tyrosinase. Then the mutant gene causing the lack is called the tyrosinase-positive albino mutant gene in spite of having nothing to do with tyrosinase. A better name would be the _____-negative mutant gene, where _____ is filled with the name of the defective enzyme. Unfortunately, we don't know the name of the defective enzyme, yet.

The Dopa Test is a biochemical test that determines whether a mutant gene is tyrosinase-negative or not. Information about it is in H.B. Bechtel's book, Amphibian and Reptile Variants.

Ideally, there is one tyrosinase-negative mutant gene and one tyrosinase-positive mutant gene. Too bad the real world does not conform to that ideal model.

In leopard geckos, there are three unrelated albino mutant genes. Nobody has done the Dopa Test on any of them. Not more than one of them can be the tyrosinase-negative mutant. Possibly none is the tyrosinase-negative mutant. 

Albino black rat snakes, corn snakes, and some others have been tested with the Dopa Test. But many others, including albino boa constrictors and ball pythons, have not. In boa constrictors, there are two albino mutants, Kahl albino and Sharp albino. Both are called tyrosinase-negative mutants without any evidence. Only one can be the tyrosinase-negative mutant, but which? And possibly both are tyrosinase positive.

In boa constrictors and some other snakes, any mutant gene that reduces the amount of, but does not eliminate, the black pigment is called a tyrosinase-positive albino mutant gene. This adds several more unrelated mutants to the mixture.

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_EverEvolvingExotics_ (09-01-2011),Jessica Loesch (09-01-2011),_slackerz_ (09-01-2011)

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## slackerz

what i know only T stand for Tyrosinase..and T+ is the presence of enzyme tryosinase which catalyze the production of melanin or black pigment.so even they are albino,they stil have black(ish) pigment like grey and others..even the color of the eye also not red and white like T- albino..so T- is the absence of tyrosinase enzyme which make them lack of melanin or black pigment..

The reason why T+ is much more cheaper,maybe they were discovered first..and T- after that and not many people still not having them..LOL. :Very Happy:

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_EverEvolvingExotics_ (09-01-2011)

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## Wh00h0069

Not bloods, but you get the point. 

T+:



T-:

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doom92muffin (09-01-2011),_EverEvolvingExotics_ (09-01-2011),Geckos-by-Pam (09-01-2011)

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