Ph.D.

Assistant Research Professor

Division of Animal Sciences

My field of research is reproductive biology with a specific focus on male fertility, sperm function, and fertilization. Besides reproductive medicine, this work profoundly affects policy making, informing major decisions concerning human reproductive health, contraception, and individuals’ reproductive rights. I have been advancing our understanding of how the ubiquitin-proteasome system (UPS), the universal protein recycling machinery, regulates the process of sperm capacitation necessary for sperm ability to fertilize eggs in humans and animals. I described the UPS-regulated, capacitation-induced re-modeling of the sperm proteome. I identified new UPS-regulated sperm proteins and developed a new protocol for selective, compartment-specific isolation of proteins to monitor their rearrangements during capacitation. I showed how the remodeling of the sperm head apex membrane can be targeted to conveniently monitor capacitation status using fluorescently labeled antibodies and lectins; and to monitor the UPS-regulated, sperm surface-seminal plasma protein de-aggregation during capacitation, before sperm detachment from the oviductal sperm reservoir shortly before fertilization. I addressed the fate of sperm proteasomes, and using my sequential isolation protocol, I showed the loss of the most abundant presence of proteasomal subunits from capacitating sperm acrosomes.

Notably, I participated in the discovery of a new biological phenomenon of sperm zinc ion release at capacitation, co-regulated by sperm UPS. Further, I discovered the biphasic regulation of the UPS activity by zinc. This discovery led to the development of a sperm fertility test and sperm processing media based on zinc optimization, the subject of our U.S. patent application. What I consider my most impacting discovery is the characterization of boar sperm zinc-binding and zinc-interacting proteome (zincoproteome), more than 1700 proteins. A portion of the boar sperm zincoproteome undergoes capacitation-related changes resulting in the up/down-regulation of their respective functions. This knowledge is being utilized in formulating zinc-based manipulation and extender media that are being developed in our lab. Further in my study, I discovered the role of neurodegenerative disease-related pathways in the process of sperm capacitation.

Educational background

• Ph.D., Charles University in Prague, Czech Republic, 2014