A T-negative albino lacks black pigment because a defective tyrosinase enzyme prevents black pigment from forming. A T-positive albino lacks black pigment because a defect in an unknown enzyme (other than the tyrosinase enzyme) prevents black pigment from forming.

I asked Dave Barker several years ago whether any boas or pythons had actually been tested for tyrosinase activity. He said no, and I have not heard different since then.

There are four possibilities:
1. The Kahl strain of albino is T-negative, and the Sharp strain is T-positive.
2. The Kahl strain of albino is T-positive, and the Sharp strain is T-negative.
3. Both strains are T-positive.
4. Both strains are T-negative.

We do not know which possibility is correct. However, as far as I know, there is only one gene locus that produces the tyrosinase enzyme. As the Kahl and Sharp strains are not compatible, there is essentially no chance that both strains are T-neg.

In other words, calling both the Kahl and Sharp strains of albinos tyrosinase negative albinos is almost certainly incorrect.

The mutants that people call T-positive albinos have some black pigment. They could produce the observed effect because of a partially functional tyrosinase enzyme or because of a nonfunctional or partially functional enzyme that has not been identified yet. For what it's worth, Siamese cats are lighter than normal cats because Siamese cats have a partly functional tyrosinase enzyme.

I'd like to see the Kahl and Sharp albinos given unique names. I'd also like to see the two anerythristics, the two caramels, and the various "T-positive albinos" given unique names. This would eliminate a lot of confusion. Anyone who can persuade the boa breeders to do this would have my unbounded admiration.

Paul Hollander

[ Hide Replies ]

• Help with Genetics document....... - rainbowsrus, Wed Apr 19 12:56:38 2006
• RE: Help with Genetics document....... - jayf, Wed Apr 19 13:45:39 2006
• RE: Help with Genetics document....... - ChrisGilbert, Wed Apr 19 14:11:52 2006
• Appreciate the pointers .. more - jayf, Wed Apr 19 14:44:03 2006
• I would also go as far as - giantkeeper, Wed Apr 19 15:15:07 2006
• RE: I would also go as far as - jayf, Wed Apr 19 16:00:29 2006
• RE: I would also go as far as - chas3323, Wed Apr 19 20:27:54 2006
• Never mind the pastel question - chas3323, Wed Apr 19 20:29:12 2006
• RE: Help with Genetics document....... - rainbowsrus, Wed Apr 19 16:34:40 2006
• I would say go with - giantkeeper, Wed Apr 19 16:52:56 2006
• Yet another question... - rainbowsrus, Wed Apr 19 17:11:20 2006
• seperate - ChrisGilbert, Wed Apr 19 20:24:16 2006
• There aren't any KNOWN T-neg albinos - Paul Hollander, Thu Apr 20 12:12:53 2006
• RE: There aren't any KNOWN T-neg albinos - rainbowsrus, Thu Apr 20 13:46:42 2006
• RE: There aren't any KNOWN T-neg albinos - Paul Hollander, Thu Apr 20 16:53:31 2006
• Thanks Paul, much appreciated....np - rainbowsrus, Thu Apr 20 17:10:51 2006
• RE: There aren't any KNOWN T-neg albinos - jayf, Thu Apr 20 13:51:53 2006
• RE: There aren't any KNOWN T-neg albinos - Paul Hollander, Thu Apr 20 16:30:43 2006
• RE: There aren't any KNOWN T-neg albinos - jayf, Thu Apr 20 17:18:22 2006
• RE: There aren't any KNOWN T-neg albinos - Paul Hollander, Fri Apr 21 13:03:01 2006
• RE: There aren't any KNOWN T-neg albinos - jayf, Fri Apr 21 13:57:54 2006
• Jungle is - giantkeeper, Wed Apr 19 13:57:42 2006
• Yes... - ChrisGilbert, Wed Apr 19 14:09:30 2006
• RE: Help with Genetics document....... - slithering_serpents, Fri Apr 21 13:00:29 2006