Marsupial conservation has taken a leap forward following the first successful production of a kangaroo embryo through in vitro fertilisation (IVF).
For the first time, researchers have produced a kangaroo embryo through intracytoplasmic sperm injection (ICSI) — a form of IVF.
Lead researcher Andres Gambini, a senior lecturer at the University of Queensland, said the achievement provided valuable insights into marsupial reproduction and the potential of assisted reproductive technology for conservation.
“Australia is home to the greatest diversity of marsupial fauna on the planet but it also has the highest mammal extinction rate,” Gambini said.
Embryo Production
Gambini said the eggs and sperm of eastern grey kangaroos, an overabundant species, were collected as a model to adapt the embryo technologies used on domestic animals and humans.“Access to marsupial tissues is challenging as they are less studied than domestic animals despite being iconic and integral to Australian biodiversity,” he said.
The development of the eggs and sperm were assessed in the laboratory before the embryos were produced through injecting a single sperm into a mature egg.
Patricio Palacios, a Ph.D. student under Gambini who was directly involved in the production, told The Epoch Times in an email that it is hard to say whether this technique can be used for all marsupials.
He said as long as an egg and a sperm are available, ICSI can be performed. However, embryo development is not guaranteed since many other factors, such as the in vitro environment and cell quality, play a role.
The technique used for marsupials is similar to ICSI for other mammals. The main differences are temperature and injection needle type.
“In marsupials, we aim for around 35°C, while in other species in our lab, we maintain 38°C,” Palacios said.
Challenges Faced
Gambini said the success with kangaroo embryos represents the culmination of years of training, research, and collaboration.Palacios said one of the main reasons it took so long was the limited access to marsupial tissues and gametes—egg cells and sperm—as they are not as widely studied as domestic animals.
Funding was also a challenge, since marsupials don’t have the same economic importance as livestock or domestic species.
“Although kangaroos are not endangered, marsupials, as a group, have the highest extinction rates among mammals,” Palacios said.
“Our current access to kangaroo samples allows us to develop this technique, which can later be applied to other marsupials and contribute to conservation efforts.”
ICSI has been attempted in other marsupial species, such as the tammar wallaby, but no live offspring have been born yet.
One of the biggest limitations is that each marsupial species has its own unique biology, meaning their specific reproductive requirements need to be understood to improve success rates.
Marsupial IVF Birth
Live marsupial births through artificial reproduction have been reported in species like the koala through artificial insemination. However, there are no reports of live births after IVF.“The biggest barriers are funding, access to samples and marsupials’ unique reproductive anatomy and physiology,” Palacios said.
Improving Preservation
Another challenge is the preservation and storage of embryos.“By developing preservation methods, we aim to safeguard the genetic material of these unique and precious animals for future use to ensure their conservation,” Gambini said.
Preservation methods will be developed based on reports from domestic species and some marsupials, mainly using cryopreservation, which requires liquid nitrogen and specialized storage facilities.
The lab is also working on new preservation strategies, such as lyophilisation—also known as freeze-drying.
Palacios said the cost of storing genetic material depends on the type of storage and duration, but it generally requires significant resources and infrastructure.
