Posted by:
jayf
at Thu May 18 21:51:21 2006 [ Email Message ] [ Show All Posts by jayf ]
I think you are a bit confused about genetics. First I would like to say I agree with what Paul said.
Second, you said that in order for the hypo gene to be dominant all the offspring of a normal to hypo breeding would be hypo. This is only true in the case of a homozygous hypo.
Each animal has two sets of genes and each gene has the equal chance of being passed onto the offspring. In the case of a heterozygous for a dominant gene animal (lets say it is a hypo) bred to a normal animal the litter would theoretically have split genetics/phenotype(appearance). Since the hypo has not only a hypo gene but also a normal gene that both have a 50% chance of being passed to its offspring (each baby has the same 50/50 chance) the litter will in a perfect world be half hypo and half normal.
Co-dominant is characterised by two distinct phenotypes(appearances) caused by one gene. In boas the best example is the motley gene. The heterozygous form looks distinclty different from the wild type as well as from the homozygous form.
I think the problem is that the hypo gene is not a pattern mutation but rather a color mutation, so it is not as easily visible. Additionally the gene does not systematically decrease pigment because if it did a homozygous animal would always have less black pigment then a heterozygous animal. This is disproven by proven/known heterozygous animals who have extreme reduction of black pigment (hypo pastels further complicate things).
I feel that it is only possible to visually determine that an hypo is not a homozygous hypo. In my eyes this is done by examining the black pigment on the tail after the vent. Although some heterozygous animals have extreme reduction in black pigment in this area, I have yet to see a proven or known homozygous hypo that does not have significant reuction of black pigment in this area (retains that dark black rings around tail blotches after the vent).
This is my feelings on the matter, and I intend to attempt to expreiment on my theory concerning the hypo gene.
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- Jason F.
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RE: $64 question on Salmon Boas - jayf, Thu May 18 21:51:21 2006