Meiosis,does the X and Y chromosomes cross over?

Question

in a cell in meiosis homologus chromosome pairs cross over. the s*x chromosome pair in male is X and Y.Y been shorter than Y ,do they cross over?

Answer 1

That's a really good question.  Crossover during meiosis is only possible for homologous (i.e. similar) regions.  Thus, a chromosome 2 can exchange material with another chromosome 2, but not with a chromosome 5.

Since the X and Y chromosomes are so different, it ought not to be possible for them to crossover.  This is basically true, but there are a few areas (especially at the ends of the X and Y chromosomes) that are homologous, and, in line with our expectations, these do seem to exchange material.

Interesting!

Answer 2

Yes. There appears to be regions of homology located on the X and Y and synapsis takes place just like with autosomal chromosomes. These are called the "pseudoautosomal regions" of each chromosome. Possibly translocations occur during the cross over; but I haven't done the research. Interesting!

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