Dosage regulation, and variation in gene expression and copy number of human Y chromosome ampliconic genes


Author summary The human genome harbors two sex chromosomes—X and Y. Among them, the Y chromosome is present only in males. Deletions of portions of this chromosome have been linked to male infertility, however exactly why the loss of these genes leads to this condition is not well understood. Here we study a group of Y chromosome genes called ampliconic genes, which are expressed in testis and are frequently deleted in males with infertility. These genes are organized in nine gene families, each of which harbors multiple copies of genes highly similar in sequence. In this study, we aimed to establish a baseline of their variation in copy number and in gene expression—one measure of genes’ functional output—by studying 149 healthy men. We found that testis tolerates a wide range of copy number and expression variation of Y ampliconic genes. Additionally, we demonstrated that gene expression within most Y ampliconic gene families depends on the expression levels of gene family members located outside of the Y chromosome, i.e. they undergo dosage regulation.

PLOS Genetics