Pierre Leclerc, PhD

My research interests aim at a better understanding of the mechanisms involved in gamete interactions, with a particular emphasis on spermatozoa. The sperm cell must undergo numerous modifications at the membrane and intracellular levels to become capable of interacting with the egg and fertilizing it. Thus, the properties of its plasma and acrosomal membranes will be affected, thereby modulating intracellular ion content, leading to post-translational modifications of several proteins, ultimately resulting in changes in the activity of various enzymes and sperm activities. This post-ejaculatory phenomenon, called capacitation, normally occurs in the female genital tract during the transit of spermatozoa towards the site of fertilization. I am particularly interested in the different intracellular signaling pathways, their control mechanisms during capacitation, and their effects on sperm functions. Furthermore, since the spermatozoon is a highly differentiated cell devoid of transcriptional and translational activities, these intracellular mechanisms control its motility to reach the fertilization site, interact with and fertilize the oocyte, and finally activate the zygote development process.

Another aspect of my research aims to directly study the binding and recognition mechanisms between the spermatozoon and the zona pellucida of the egg by investigating the role of the sperm protein SPAM1 in these phenomena. A better characterization of this protein, the changes in its properties during capacitation, and the importance of these changes for sperm binding to the oocyte are central to my research.

Furthermore, in the context of the agri-food industry where reproduction plays a crucial role and where artificial insemination is a major player, it is essential that spermatozoa are preserved under optimal conditions to ensure reproductive success. Therefore, I am studying the effect of freezing (cryopreservation) on the survival and fertilizing ability of spermatozoa by evaluating ways to improve the procedure.

A better understanding of the mechanisms involved in acquiring fertilizing ability and sperm/egg interactions is important in farm animals where the profitability of the enterprise often depends on the reproductive efficiency of the animal. In humans, the sperm/egg interaction is of particular concern in cases of infertility diagnosis/treatment or in the development of new contraceptive methods. Various research projects are currently underway on these topics in my laboratory.

Tania Lapierre
MSc student
tania.laperriere.1@ulaval.ca

Édith Gosselin
MSc student
edith.gosselin.4@ulaval.ca

Rohit Kumar Deshmukh
PhD student
rohit-kumar.deshmukh.1@ulaval.ca

Gilles Malherbe
Research professional
gilles.malherbe@crcudequebec.ulaval.ca