The Comparative Reproductive Biology of Mammals Group

Contact: A/Prof. Bill Breed.

Our research focuses on the morphological diversity of gonads and gametes of Australian mammals and how the diversity that has evolved relates to function. For our work we use a variety of light and electron microscopical techniques. We have several current research programs that encompass questions around studies on the evolution of the mammalian ovary and testis as well as the eggs and sperm that are produced.  For most of our studies we use various Australian native mammals including, at the present time, koalas, wombats, bilbies, hopping mice, plains mice and various other native rodents. We have also carried out, in the recent past, various studies on gamete interactions at the time of fertilisation and one of our current interests is on the selective pressures that bring about molecular evolution of the sperm binding site on the egg coat, the zona pellucida. We have found dramatic differences occur in sperm morphology in closely related species and we are currently exploring the possible reasons for this. In addition we have found that some of the Australian rodents have evolved, what appears to be, the most morphologically complex sperm form in eutherian mammals.  Apart from these studies on mammalian gamete and gonad diversity, we also have ongoing studies on the environmental control of gonadal function of Australian mammals and how the reproductive system of these animals is adapted to the challenging environments in which the animals occur.

Current Research Projects

• Evolution of sperm form in native rodents and its relation to function
• Factors determining testis size and sperm production rates in Australian mammals 
• Effects of environmental temperature on quality and quantity of sperm production in arid zone rodents
• Extratesticular sperm maturation in the male and female reproductive tracts
• Organisation of the extracellular matrix of the egg coat, the zona pellucida, and in particular the evolution of the sperm binding region
• Application of reproductive technology, and in particular sperm cryopreservation, to conservation of gametes of threatened species especially native rodents
• Application of pouch young swapping to marsupial conservation programs
• Coevolution of the male external genitalia and the female reproductive tract.

Professional research staff: Assoc. Prof. Bill Breed, Emeritus Prof. Brian Setchell, Dr Eleanor Peirce, Dr Mario Ricci, Dr. Dave Taggart and Mr Chris Leigh.

Collaborators: Prof. Richard Oko (Queens University, Kingston, Ontario, Canada), Dr. Jamie Chapman (University of Tasmania),  Dr. Mike Kokkinn (University of South Australia), Dr. Mike Carleton (National Museum of Natural History, Washington), Dr. Steve Goodman (Field Museum of Natural History, Chicago), Dr. Ken Aplin and Dr. Fred Ford (Australian National Wildlife Collection, Canberra), Prof. Harry Moore (University of Sheffield).

Research Students: Elisa Sparrow, Liberty Olds, Karleah Trengove, Harsha Wechalekar, Tasha Speight, XiaoDan Ding.