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How can a male be Het for something?

P

palousepony13

New member
I've been contemplating this all morning. I have a male corn that was sold to me as a Miami phase, het for crimson. How can a male be heterozygous? Females can be because they go through X chromosome inactivation, and have an allele that isn't expressed. But males only have one X chromosome, and don't go through X inactivation. So they should express the trait. Could this just mean that he will show the crimson phenotype, but can only pass on one copy to his progeny? Or is this a Y-linked trait? I didn't think there was much on the Y- chromosome but DNA coding for hormones and a few secondary sexual characteristics. But I could be wrong.

If saying that he is het for something just indicates that he only has the single allele for crimson, why wouldn't all males be labeled as het for their recessive traits?

**Update: I pulled out all my genetics textbooks, and it showed that the genes for coloration/patterns must be on any of the chromosomes other than the X/Y sex chromosomes. This pretty much answers my question (and makes me feel like an idiot for not figuring it out), but I couldn't get this post deleted - it wouldn't let me. Sorry.
 
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Not all mutations are on the X-chromosom. That's why :)
In fact most mutations are recessive and on other chromosomes than the X.
Hope that helps - my english isn't the best:(
 
Thanks. I pulled out my genetics text books, and felt like an idiot after I posted this, because the answer was so simple. I got caught up on the whole sex-linked calico cat coloration that we discussed in class that it carried over to my perception of cornsnake morphs. Thanks. I tried to delete the post after I figured it out, but I can't seem to. But I really appreciate the answer.
 
genetics of calico cats

I had to swot up on calico cats years ago because we have some. Did your text parrot the sexlinked black fallacy? Mentioning the X inactivation makes it seem fairly up to date and likely to know that the black mutant is autosomal.

BTW, colubrid snakes don't have X and Y chromosomes. Males have two large Z chromosomes, and females have a large Z and a smaller W chromosome. This is the same pattern of sex chromosomes that's in birds. Though with the possible exception of brindle in the black rat snake, I haven't heard of a sexlinked mutant in any snake.
 
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