Comparative Biology of Mammalian Sperm and Eggs

Research Leader: Associate Professor Bill Breed

The Comparative Biology of Mammalian Sperm and Eggs group is interested in the diversity of life, its evolution and its conservation. As comparative mammalian reproductive biologists the group's main focus is on a study of the evolution of sperm and oocytes (eggs) together with the molecular and cellular processes that take place at the time of fertilisation.

Recently the group investigated the molecules involved in the sperm binding to the oocyte coat glycoprotein, the zona pellucida, and we have found evidence for some differences between closely related species, suggesting the occurrence of positive selection acting on these molecules.

The group also studies the effects of high body temperature on sperm function (with a view to making predictions as to possible male fertility effects of global warming) and we have found that in house mice, and even in arid zone adapted native Australian rodents, there is an increased incidence of apoptosis in sperm residing in the epididymis when animals are exposed to environmental temperatures just a few degrees higher than that of core body temperature.

Research Priorities:

• Coevolution of male and female gametes and reproductive tracts in rodents
• Selective pressures on oocyte coat receptors for sperm binding proteins
• High body temperature effects on sperm quality
• Structural and functional significance of interspecific differences in acrosomal morphology
• Evolution of sperm head cytoskeleton and its functional significance
• Effect of population size on reproductive fitness in marsupials with species reference to wombats