The Y chromosome.
The Y chromosome has evolved to provide sex determination in mammals. In association with its evolution, genes important for spermatogenesis have been sequestered on this chromosome. Further, X chromosome inactivation has developed as a mechanism to prevent over-expression of genetic factors important for somatic function in females, with maintenance of their activity in males. The multi-repeat organization of the Y chromosome and limited regions of crossover with other chromosomes predisposes it to internal recombination and loss of genes that may be important for spermatogenesis. Y chromosome microdeletion testing of infertile men with non-obstructive azoospermia provides prognostic information useful for management of these patients. In the presence of a complete deletion of the azoospermic factor a (AZFa) or AZFb regions, sperm retrieval is highly unlikely. Recent advances in our understanding of the organization and function of the Y chromosome are likely to enhance further the role of the Y chromosome in normal spermatogenesis and fertility.
Schlegel
Peter N
PN
Department of Urology, The New York Presbyterian Hospital-Weill Medical College of Cornell University, New York, NY, USA. pnschleg@med.cornell.edu
D000818:Animals; D005075:Biological Evolution; D005260:Female; D017353:Gene Deletion; D020868:Gene Silencing; D006801:Humans; D008297:Male; D019849:Sex Determination Processes; D013091:Spermatogenesis / Q000235:genetics; D014960:X Chromosome / Q000502:physiology; D014998:Y Chromosome / Q000502:physiology*