The molecular fingerprint of human spermatogenesis

Spermatogenesis is a complex biological process in which diploid spermatogonial stem cells divide, differentiate and mature into haploid spermatozoa capable of fertilizing an oocyte. This entire process can be divided into three main phases and associated germ cell subtypes: a pre-meiotic phase (spermatogonia), a meiotic phase (spermatocytes) and a post-meiotic phase (spermatids). A disruption during any of these phases can lead to male subfertility. In rodents, it is well documented that spermatogenesis is regulated by key molecular drivers. In this thesis we generated gene expression profiles for six human germ cell subtypes, extracted from fertile men, giving us a molecular fingerprint of normal human spermatogenesis. Likewise, using samples from men suffering from meiotic arrest, we also generated a molecular fingerprint of spermatogenesis disrupted at the meiotic phase. Comparing these two molecular fingerprints allowed us to uncover important drivers of human spermatogenesis that are crucial in ensuring male fertility. These molecular fingerprints can be used as a foundation for further research in reproductive biology but also provide useful information for personalized reproductive medicine.