Female Reproductive Biology

Female Reproductive Biology

Female reproductive biology is one of the central fields in reproductive sciences. From the moment of conception, our biological sex is determined by our sex chromosomes. Females have two X chromosomes (XX), while males have one X and one Y chromosome (XY). However, certain genetic anomalies or variations in sexual development can interfere with the sex determination process. Cases of sex reversal—where an XX individual develops male characteristics or, conversely, an XY individual develops female characteristics—are among the areas of interest of the research teams led by Nicolas Pilon and Robert S. Viger. More specifically, Nicolas Pilon studies sex-related disorders such as Hirschsprung’s disease, which is four times more common in boys than in girls, and CHARGE syndrome (subfertility and male-to-female sex reversal). Robert S. Viger investigates the factors involved in sex reversal as well as diseases of the female reproductive system such as endometriosis, polycystic ovary syndrome (PCOS), and breast cancer.

Ovaries
The ovaries are the primary female reproductive organs, located on either side of the uterus. Their main functions are twofold: to produce eggs (oocytes), which are the reproductive cells, and to secrete hormones such as oestrogens and progesterone. Several researchers in the RQR focus on ovarian function. Derek Boerboom studies the signalling pathways involved in follicle formation (small sacs that surround and protect the oocytes) and the preservation of eggs in the ovaries. Dysregulation of these pathways could contribute to various reproductive system diseases, such as ovarian, uterine, or breast cancer.

Before an egg can be fertilised, it undergoes a maturation phase in the ovary. During this time, it grows and stores everything needed for the very early stages of embryo development. This growth and maturation are essential for the egg to successfully give rise to a healthy embryo after fertilisation. Within the RQR, many labs study different aspects of ovarian function, including those of Hugh J. Clarke, Raj Duggavathi, Antony Estienne, Bruce Murphy, François Richard, Gustavo Zamberlam, Christopher Price, Teruko Taketo, Marc-André Sirard, Greg FitzHarris, and Nicolas Gévry.

One of the diseases affecting the ovary is ovarian cancer, which may be influenced by hormonal factors, genetic mutations, or environmental influences. The teams of André Tremblay and Yojiro Yamanaka investigate the mechanisms underlying the development of this cancer.

Hormones
The function of the female reproductive organs is regulated by hormones. Each cycle, a few follicles—each containing an egg—develop under the influence of follicle-stimulating hormone (FSH), which is produced in the brain. In turn, FSH production is regulated by another hormone called gonadotropin-releasing hormone (GnRH). Daniel Bernard’s lab studies how FSH is synthesised in the brain and how GnRH acts. The neuroendocrine control of reproductive function is also a focus of Mauro Silva’s research, which includes the regulation of GnRH and polycystic ovary syndrome (PCOS).

Uterus
The uterus, under the coordinated influence of oestrogens and progesterone, prepares each cycle for a potential embryo implantation. Éric Asselin’s lab aims to understand how cells survive or die when the embryo implants in the uterus or when the endometrium prepares for pregnancy. His team also studies what happens in certain diseases, including why some cancer cells in the uterus or ovary resist chemotherapy.

Pregnancy
During pregnancy, the mother's body adapts in many ways to support the baby’s development: the immune system adjusts to avoid rejecting the fetus, hormones maintain the pregnancy, and blood vessels change to nourish the placenta properly. But sometimes these adjustments fail. This is the case with preeclampsia, a complication in which blood pressure rises and the placenta functions poorly. This can endanger both the mother and the fetus, and premature delivery is often the only available treatment. Julie L. Lavoie’s team studies the mechanisms that lead to preeclampsia to develop new therapeutic strategies.

Certain infections during pregnancy can also pose risks to the baby. One example is toxoplasmosis, a disease caused by a parasite called Toxoplasma gondii. If a woman becomes infected for the first time during pregnancy, the parasite can cross the placenta and reach the fetus, sometimes causing serious brain or eye damage. Maritza Jaramillo’s team investigates how toxoplasma infection alters placental function and affects fetal development.

Vagina
The vagina naturally hosts billions of microorganisms, mainly lactobacilli, which form a protective barrier. When this microbial community is well-balanced, it helps prevent infections, promotes fertility, and supports healthy pregnancy outcomes. In recent years, many studies have highlighted the importance of these microbes in women’s reproductive health. Yet, their role remains under-recognised in clinical care. Karine Dufresne’s research focuses on the relationships between the body and vaginal bacteria.

Mammary Gland
Lastly, the breast, a major target organ of sex hormones, is central to research on breast cancer, the most common cancer in women. Nicolas Gévry’s lab specifically investigates the mechanisms involved in the development of triple-negative breast cancer, a particularly aggressive form of the disease.