About our research
We are currently investigating viviparity (live birth/pregnancy), the placenta, and birth.
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Viviparity and Pregnancy
Viviparity is one of the most important biological innovations as its evolution has required a set of complex phenotypic changes to allow internal incubation of embryos, radically changing the way in which organisms interact with their environment and transmit their genes to the next generation. Viviparity has evolved repeatedly from oviparity >150 times in a diverse array of vertebrates. We are testing whether pregnancy is controlled using the same genes and physiological processes, or via divergent pathways due to different ancestry and evolutionary constraints.
We are currently investigating the biology and evolution of pregnancy in a variety of non-traditional model organisms, including lizards, seahorses, sharks, and Australian marsupials. Some of our favourite model species are lizards which have both oviparity, viviparity, and a transitional form of pregnancy in different individuals (read our review here). Some of the questions we are working to answer include:
- How is it that some lizards lay eggs, whilst others of the same species give birth to live young?
- We've observed both egg-laying and live birth in a single pregnancy. So can oviparity 're-evolve' from viviparity?
Biology and Evolution of the Placenta
Placentae have also evolved convergently in vertebrates many times, including at least 16 origins of a complex, nutritive placenta. Read our review of vertebrate placentation here. Placentae have evolved independently, from many different tissues, and we have shown that the evolution of the placenta is far less predictable than originally believed.
Some of the questions we are working to answer include:
- Can male seahorses transport nutrients to developing embryos?
- What nutrients do male seahorses transport?
- How does a shark placenta work?
Parturition (birth)
There are some common triggers for labour in mammals, lizards, and seahorses, and we have discovered that these mechanisms (e.g. oxytocin) can be deployed in the same way, or new ways each time pregnancy evolves.
Some of the questions we are working to answer include:
Venom
As well as contributing to the platypus genome sequencing project, we examined the genetic basis of venom in the platypus and other mammals. This research has resulted in breakthroughs of our understanding of key mechanisms of mammalian venom gene evolution, including recruitment from non-toxin genes, gene duplication to form multigene toxin families, alternative splicing and mutation, and convergent evolution of venom toxins between the platypus and other unrelated species. The novel putative venom toxins that we have identified represent promising candidates for future pharmaceutical development.