What does the koala genome tell us about their reproduction and development?
New findings on koala reproduction enlighten us further about the uniques and specialised development that takes place in young.
Koalas are induced ovulators, which means they only ovulate in response to mating. Genes known to be involved in male induced ovulation were found in the koala genome (also highly conserved in other induced ovulators such as camels and llamas) suggesting a role for male koalas in inducing ovulation.
Like all marsupials, koalas do most of their development in the pouch. They are born after 34-36 days gestation and spend ~6 months developing before emerging from the pouch. As for other marsupials, the development of koala young depends on a supply of milk that changes in composition during pouch life. Thanks to the high-quality genome, we were able to analyse and discover koala-specific milk proteins that are critical for various stages of development. Excitingly, these proteins seem to have an antimicrobial role, showing activity against a range of bacteria and fungal species, including the strain of Chlamydia pecorum known to cause ocular and reproductive disease in koalas. This would be vital in the early stages of development, when the koala young lack a functional immune system.
Dr Rebecca Johnson , Director, Australian Museum Research Institute