>1. The no-melanin type Albinos are up in the air to if they are T-Pos or T-Neg.

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>2. However, the other bloodlines that show a visible reduction in black pigmentation, if caused by a single gene*, these have been simple recessive so far, those could all be technically classified as Tyrosinase Positive Albinos. This regardless of pink pupils or not correct? Regardless of the amount of apparent black in the rings around the tail blotches correct? This varies greatly even within a single bloodline and may change with age. All this because Albinism is expressed in a wide range of ways correct?

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>Do I have that correct?



Point 1 is correct, and point 2 is mostly correct. I see no reason why salmon (AKA hypo) could not be classified as a tyrosinase positive albino. It is certainly T-positive. Depending on how far you want to stretch the definition of "albino", even pastels could be included.



Variation in the amount of black within a bloodline is called "variable expressivity". It can be caused by a variety of other genes and by environmental factors. For example, a mild copper deficiency can affect the amount of black pigment produced.



>True black is not something that can necessarily be picked up with my eye. Is that a true statement? I am thinking that black production or melanin production my be interrupted on some level but may or may not be discernable with the human eye. Is that correct?



I'm not sure what you mean by "true black". This is starting to sound like the question of whether a falling tree makes a sound if nobody is there to hear it.



As the easterners say, a journey of a thousand miles begins with a single step. Which, among other things, means that there are many steps in the journey, and a stumble can happen at any step in the journey. Some stumbles are worse than others, of course.



For what it's worth, there are mutant genes that sometimes show their effect to the eye and sometimes do not. Then the only way to identify an individual with the gene is by breeding test or sophisticated physical or biochemical tests. This sort of thing is known for both dominant and recessive mutants. See "penetrance" in Wikipedia.



Paul Hollander

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