Cristian O'Flaherty


Cristian O'Flaherty


Associate Professor, Department of Surgery, Division of Urology, McGill University
Associate member, Department of Pharmacology and Therapeutics, McGill University
Associate member, Department of Medicine, Division of Experimental Medicine, McGill University

Area of Research: Andrology; Molecular basis of spermatogenesis and epididymal sperm maturation; Acquisition of fertilizing ability by the spermatozoon; Male infertility

Contact Information:

cristian.oflaherty [at] (Email)

Tel: 514-934-1934, ext. 35410

Recent Publications:


Research Interests:

  • Redox signaling in spermatogenesis, epididymal maturation and sperm activation
  • Regulation of apoptosis in the testis
  • Phosphorylation events involved in sperm activation
  • Male infertility
  • Toxicology of male reproduction

Summary of Work:

We are interested in the molecular mechanisms that drive the production of mature spermatozoa and their modulation by reactive oxygen species (ROS). These active molecules, such as superoxide, hydrogen peroxide and nitric oxide, have dual effect on cellular metabolism. The oxidative stress, a condition characterized by high levels of ROS and/or low levels of antioxidant systems, can induce damage on spermatogenesis and sperm maturation, leading to an increase of defects in the sperm genetic information, motility machinery and the acquisition of fertilizing ability by the spermatozoon. On the other hand, when ROS are produced in low and physiological conditions, they trigger and modulate signaling events that allow the spermatozoon to have fertilizing competence.

However, little is known regarding the molecular mechanisms affected by oxidative stress and how ROS can disturb the machinery to produce spermatozoa. Agents present in the environment (i.e. pesticides, phatalates, and dioxins), drugs (chemotherapy) and even diseases (i.e. cancer) can affect men fertility. These conditions are often associated with high levels of ROS and could contribute to infertility. Moreover, ROS are present in high concentration in semen from men with idiopathic infertility.

Therefore, our research program is designed to identify signal transduction mechanisms modulated by ROS during spermatogenesis, epididymal sperm maturation and then in mature spermatozoa for the acquisition of fertility. Particularly, we are interested in the modulation of gene expression, transcription and post-translational protein modifications by ROS. These studies will bring a better understanding of the pathophysiology of male infertility and lead to the development of novel both diagnostic and therapeutic approaches to help men with idiopathic infertility and cancer patients that are facing infertility problems due to the chemotherapy.




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