Jeff's discussion above is correct with regard to the cross of homozygous recessive "albino T" X homozygous recessive Sharp albino - it would yield 100% double hets and no visuals so long as the genes for these traits do not reside at the same locus (the Sharp albino locus). If the "albino T" was yet another allele occurring at the Sharp albino locus, then all of the offspring should be the intermediate visuals (parallel to Sharp X Caramel-hypo = all paradigms). This litter does not fit either of these two possibilities.

I think that parthenogenesis is unlikely as I have not heard of a litter (or single group of offspring of anything of any kind) consisting of some that were produced sexually and some that were produced asexually (i.e. by parthenogenesis). That doesn't mean it's not possible, but all the information I have seen suggests that parthenogenesis is an all or nothing kind of deal (I have done a lot of research on this topic of late, and will soon be posting about a very curious litter of my own after I've had a chance to think it through a little more ) - of course it could also be that you just wouldn't usually have any reason to suspect that some in a litter/offspring group were sexually produced and others parthenogenically produced.

Some other considerations......

How "well proven" are the genetics of the "blonde albino T"? Is it absolutely certain that this is a simple recessive trait?

How certain is it that the visuals in the litter are not just exhibiting "albino T"? Is the tongue color possibly within the normal range of variability, or possible related to size/age?

If the "albino T" trait were dominant and the mother heterozygous for this trait (i.e. she'd be a visual het, as with the Salmon-hypo and Motley genes, for example), then that would open up the possibility that the 4 visual offspring are "albino T" OR that the "albino T" allele does reside at the Sharp albino locus and that in combination with a Sharp albino allele produces a new visual intermediate morph, paralleling the paradigm genetics. In either of these two scenarios, this litter would just be a case of bad odds. To make the numbers more convenient, the expected number of visuals in a litter of 20 for each of these scenarios is 10. Having got 4, the probability of deviating 6 or more from the expected result of 10 is 1.2% - not impossibly bad odds, but pretty bad.

If the "albino T" trait is recessive and the mother is homozygous for this trait, it could be that the Sharp male is het for this trait and that it is completely unrelated to the Sharp albino locus. With this scenario, the same 1.2% bad odds apply (because the number of expected visuals is again 10 in a litter of 20).

If the "albino T" trait were dominant and the mother heterozygous for this trait, the "albino T" allele could be combining with an unknown recessive allele carried by the Sharp male at a locus other than the Sharp albino locus and creating an intermediate visual morph. In this case, the expected number of visuals in a litter of 20 would be 5, and so 4 is a very likely outcome.

Finally, it could be that the male and female are both heterozygous for a previously unknown recessive trait that has expressed itself in 4 of the offspring - here again, 4 would be a very likely outcome as the expected number of visuals would be 5 in a litter of 20.

I don't particularly care for any of these possible scenarios based on what I know at the moment - I was just trying to throw out any possibilities I could think of. However, I would be very interested to find out how much is really known about the genetics of the "blonde albino T" trait itself, because if it is NOT simple recessive then more of the above possibilities open up. Alternatively, if it IS simple recessive, then the only scenarios above that apply have a rather low probability of occurrence suggesting that the answer may lie elsewhere yet!

Any info on the work done toward proving the nature of the "albino T" genetics may be helpful - pardon my ignorance on this one, I just have not followed its development closely.
Thanks!

Steve Reiners
BoaMorph
www.BoaMorph.com

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