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Male Germ Cells

Theme leader : Dr. Robert Viger, Université Laval

Problem: The causes of male infertility are not well understood. There is mounting evidence that most epigenetic patterns of male germ cell stem cells are established during embryonic development. The continuous production of large numbers of spermatozoa, as well as the complex chromatin packaging that occurs during spermiogenesis and sperm maturation, are under exquisite endocrine and paracrine control. Many elements of the process, including the role of DNA methylation and histone modifications remain undiscovered. Sperm produced by the testis undergo a complex postspermiogenic process of maturation in the epididymis and the female reproductive tract. Many elements of this long developmental trajectory remain obscure and even less is known about the impact of aging and environmental factors. While the phenomenon of transgenerational epigenetic effects of xenobiotics is now well substantiated, the mechanisms are mostly unknown. 

Plan: Spermatogonial germ cell niches and renewal will be investigated using novel transgenic models and stem cell transplantation. The new tools of global genomic, proteomic and epigenetic investigation will focus on understanding pituitary and Leydig cell interactions, steroidogenesis and androgen actions on spermatogenesis. The mechanisms by which the epididymis regulates sperm maturation as well as semen proteins and postejaculatory events of capacitation and the acrosome reaction and will be examined using both novel and classic technologies. The RQR will take a comprehensive, multidisciplinary approach to the study of xenobiotic influences on stem cell renewal, spermatogenesis and sperm maturation, with focus on male-mediated adverse progeny outcome, transgenerational epigenetic mechanisms, and reproductive toxicology. We are in a unique position to make pivotal contributions to this field in the coming years.

 

Summary of the 1st theme meeting during the RQR Symposium

Summary of the theme meeting during the 3rd symposium of the RQR (November 17th 2010)