Within CRDSI, researchers focus on developmental processes such as gametogenesis (production of male and female gametes), gonadogenesis (differentiation of gonads and their specialized cell types), early embryogenesis, foetal and perinatal development and hormonal regulation of puberty.
On the male side,Guylain Boissonneaultis interested in the spermatogenesis process and how extreme DNA compaction can occur while preserving the integrity of the genetic material. Robert Sullivan and Clémence Bellannée demonstrated, amongst others, that following the release of spermatozoa in the lumen of the seminal tubule, gametes undergo various modifications enabling them to acquire their fertilizing power during epididymal transit. In preparation for its meeting with the oocyte, spermatozoa must undergo various important structural changes in order to be able to cross the different protection layers of the oocyte for fertilization. Pierre Leclerc andJanice Bailey study the fundamental mechanisms of the molecular cascade responsible for the fertilizing power of the male gamete. Robert Viger andJacques J Tremblay apply their molecular biology and endocrinology knowledge to study the network of molecular and hormonal factors that control morphogenesis and differentiation of somatic cells (Sertoli, Leydig) of the testis – this expertise is paramount for a better diagnostic of sexual development disorders, developmental abnormalities often found in the human population but remain poorly understood.
On the female side, Marc-André Sirard and François Richard study folliculogenesis, which corresponds to the recruitment and growth of ovarian follicles. The growth of each follicle is supported by the combined effect of many hormones that stimulate the growth of the follicle and of the gamete it contains. Knowledge remains very limited on the sequence of steps and signals leading to the production of a follicle within which the oocyte has acquired the required competencies to sustain post-fertilization development until the embryo takes charge of its own destiny. François Richard studies how follicular cells control oocytematuration while Marc-André Sirard studies how these signals impact on the quality of the oocyte. As mentioned, the quality of the oocyte determines the success of embryogenesis. Claude Robert studies the exchanges between follicular somatic cells and the oocyte and their impact on the future of the embryo.
The research interest of CRDSI researchers do not end with early embryo development but carry on through foetal and perinatal development. Yves Trembay’s team is interested in foetal development and the gene expression of steroidogenesis enzymes specialized in the metabolism of sexual steroids in the placenta and foetal lungs. Indeed, the androgen and estradiol synthetized by foetal lungs and the placenta, respectively, control through their specific tissue expression key events of foetal development and in both cases, a spatio-temporal disruption in the metabolism of these steroids during pregnancy is directly linked to developmental pathologies. The innovating work of Emmanuel Bujold and Nils Chaillet, which bridge fundamental and clinical research, tackle the problem of predicting and preventing major obstetrical syndromes (in utero death, preeclampsia, premature labor, premature membrane rupture, intra-uterine growth restriction).
- Period: 2016-04-01 2018-03-31
Partnership, Natural Sciences and Engineering Research Council of Canada, Collaborative REsearch and Develpment grant (RDC)
Programme de recherche en partenariat pour l’innovation en production et en transformation laitières - VII - Volet génomique, protéomique et métabolomique
Genetic selection has enabled considerable increases in dairy production. Only since 2005, the average for the Holstein breed has increased 5%, representing about 500kg of milk per year per cow. Despite a higher productivity, producers are concerned about the health and fertility traits of their animals. A decrease in performance for these traits involve important economic losses since the increase in costs for treating and replacing animals surpasses the gain in productivity. In addition, diminished health and fertility result in a higher cull rate and thus a higher number of animals on the farm to ensure replacement, which goes against sustanability objectives. In this project, we will develop a completely different genetic selection approach. The key principle at the core of genetic improvement is that individuals present differences in their DNA sequence and that these differences are responsible for differences in performances. The current models are linear, which implies the best performances are achieved by animals carrying a large number of regions with two identical DNA copies. In other words, current genetic evaluation are detrimental to animals carrying a certain genetic variability. This project relies on the well known fact that health and fertility traits respond well to inter-breed crossbreeding. We hypothesized that it is possible to choose complementary parents to ensure a diversity in regions known to be involved in the expression of health and fertylity traits without affecting the rest of the genome in order to preserve the gains made at the dairy production level. At completion, the project aims to develop a new way to select reproduction animal in terms of genetic complementarity in order to improve health and fertility traits. This will help dairy producer increase their revenues and improve the sustainability of their production.