Fly Eye

Fruit Fly Eye Colour?

Sepia eyes is recessive and autosomal denoted by "sese"
Red eyes are dominant and sex-linked denoted by "R"
White eyes are recessive and sex-linked and denoted by "r"

If you have a male fruit fly that has sepia/black eyes, it would be homozygous recessive "sese" right? But since its autosomal, its not on any of the sex chromosomes. So if you have a sepia eyed fly, what alleles would be on the sex chromosomes of that fly?

Basically, what I'm asking is, if you have a male fly that has the white recessive allele on its X chromosomes and is homozygous recessive for sepia (sese), which colour would dominate?

Can you please leave a source with your answer?
Thanks a bunch

From the information given, a sepia-eyed male fly would have to have the genotype rY (at least, that's what I would conclude), because there must be SOME allele on his X chromosome, and it's not R because the informtion says that R is dominant and se is recessive. Therefore, the presence of an R allele would automatically make the eyes red. Is there another allele for the autosomal gene? This would be important.

My first response to the information would be: Show me a white-eyed male, because it seems that a male cannot have white eyes. That is, the order of dominance is R > se> r.