Characterization of the AZF region of the Y chromosome in Native American haplogroup Q

The Y chromosome is a genomic niche for genes involved in male gamete production. The existence of an azoospermia factor (AZF) in its long arm is a key genetic determinant for spermatogenesis since its deletion is associated with infertility. Deletions in the AZFc region are the most frequent known genetic cause of male infertility. This region contains eight gene families involved in spermatogenesis, including Deleted in Azoospermia (DAZ) and the Chromodomain Protein Y (CDY) genes. AZFc displays significant variation across the male population; nonetheless, the phenotypical consequences of some of these variants remain unclear. Many Y-chromosome geographically differentiated haplogroups have been defined in the human population. However, the information available on the Y chromosome sequence in GenBank belongs only to the European haplogroup R. Recent studies have shown that high mutation rates have driven extensive structural polymorphism among human Y chromosomes. Normal males belonging to different Y chromosome haplogroups showed large-scale differences from the reference sequence. In Native American populations the more frequent haplogroup is Q1a3a1 and is still present in the extant Argentinean male population. The hypothesis of this Master Thesis was that individuals belonging to different Y-chromosome haplogroups might carry characteristic rearrangements on their Y chromosomes. Thus, the aim of this work was to detect microdeletions in the AZFc region of the Y chromosome and to quantify CDY and DAZ gene copy number in fertile men belonging to Native American haplogroup Q1a3a1. INSTITUTION: School of Pharmacy and Biochemistry, University of Buenos Aires, Argentina.