XYZWs of Sex Determination

In mammals, birds and some reptiles, sex is determined by sex-specific chromosomes.  In mammals, the sex-determining chromosomes are called X and Y, and only males have both.  In birds and reptiles, these chromosomes are called Z and W, and only females have both. How are these related to one another and to the rest of the genome?  Do the X chromosomes of all mammals have similar genes?  Do all birds have similar Z chromosomes?  Are the Z chromosomes of birds and reptiles genetically similar?  How do all of these chromosome participate in sex determination?  Come and find out some of what we do and don’t know about these interesting questions.

By Dr. Mary Anne Clark