Researchers unveil five new AI koala babies
First there was one, and now there are six baby koalas - the world's first marsupial offspring born following artificial insemination of their mothers.
University of Queensland and Lone Pine Koala Sanctuary today announced the existence of a further five koala babies born by means of artificial insemination.
The release of this information follows the previous announcement early this year of the world's first koala birth using artificial insemination. Researchers say it serves to highlight both the reliability and repeatability of the technique in this species.
The five pouch young, who have been called Watson, Elise, Meg, Gypsy and Maggie by Lone Pine Koala Sanctuary staff, now join the shy, unnamed first koala baby as the only marsupials born via artificial insemination.
The birth of these babies represents a major achievement for University of Queensland researchers Steve Johnston and Dr Michael McGowan, and Lone Pine Koala Sanctuary's head curator Paul O'Callaghan, who have spent more than five years developing the successful protocol.
Dr McGowan said the first reported AI koala baby was now five months old, furred, and just starting to poke its head out of its mother's pouch. The kitten-sized baby was growing well.
In preparation for artificial insemination, the baby's mother, Robyn, was given a hormone which caused her to ovulate at the appropriate time. Thirty-five days later the baby was born and within a minute had crawled into its mother's pouch and attached to a teat.
The new AI koala babies announced today were conceived as part of the pioneering studies which investigated the mechanism of ovulation in the koala. These studies showed that the physical act of mating (but not ejaculation) triggered the release of the egg from the ripe follicle on the ovary. The mothers of the koala babies - Elle, Louise, Twinkles, Pixie and Lil - were induced to ovulate by allowing a teaser male to mate with them, and then they were artificially inseminated with semen from a donor male.
To be absolutely certain that the offspring produced by these mothers resulted from the insemination of donor sperm, rather than premature ejaculation of sperm from the teaser male, paternity exclusion analysis was performed by Dr Bronwyn Houlden of Taronga Zoo. This analysis revealed that all five babies had been produced by donor sperm.
Studies crucial to the overall success of the artificial insemination program included developing a technique for semen collection by means of an artificial vagina; developing methods for short and long-term storage of koala semen; and the characterisation of the koala oestrous cycle.
The researchers collaborated with leading endocrinologist Dr Ron Cox at Bioquest Ltd Sydney, who conducted hormone assays on blood samples collected by Mr Johnston and Mr O'Callaghan to document changes in hormone levels in the koala's oestrous cycle.
Mr Johnston said artificial breeding of koalas had a number of advantages for both their wild and captive conservation and management.
"Basic reproductive knowledge gained from developing the koala artificial insemination program increases our general understanding of the biology of this species and is fundamental for making informed decisions about koala management, both in captivity and the wild," he said.
"For example, knowledge of how koalas reproduce is just as important in preventing them from breeding as it is to helping them to reproduce. This issue is particularly important for island populations of koalas in southern Australia where over-population by the koala has caused severe defoliation."
Mr O'Callaghan said artificial breeding also had major implications for the transfer of male genetic material both nationally and overseas. Shipment of liquid stored or frozen semen could help to eliminate the need for transporting male koalas internationally. This had obvious animal welfare and economic advantages.
"Although koalas are under no immediate threat of extinction, the development of an artificial insemination program based on the insemination of frozen stored semen may become a useful tool to help secure the future of this species, particularly if the present rate of habitat fragmentation and urbanisation continues," Mr O'Callaghan said.
Dr McGowan and Mr Johnston said the team was seeking $100,000 funding to advance the project to the next stage of excellence. This would be to successfully freeze koala semen, so that the genetic diversity in different Australian koala populations could be preserved as an insurance against cataclysmic events such as bushfires.
The researchers will host a visit by Dr William Holt of the Royal Zoological Society of London next year to conduct experiments on methods of freezing koala sperm.
For further information, contact Dr McGowan and Mr Johnston, telephone 07 3365 5719 or Mr O'Callaghan, telephone 07 3378 1366.
