For the first time, scientists have been able to produce kangaroo embryos through in-vitro fertilization (IVF), an important milestone in being able to replicate this across hundreds of species of pouch-toting marsupials under ever-increasing threat of extinction.
A team from the University of Queensland successfully replicated nature from eggs and sperm harvested from eastern grey kangaroos (Macropus giganteus), but not because of their own threat of extinction. The animals actually number in their millions and are adept survivors. However, many of their marsupial relatives are not as fortunate, and due to habitat loss, the development of roads, heat stress and invasive species, they face an uphill battle for survival. So, it's forced scientists to get a little more 'creative.'
“Australia is home to the greatest diversity of marsupial fauna on the planet but it also has the highest mammal extinction rate,” said lead researcher Andres Gambini. “Our ultimate goal is to support the preservation of endangered marsupial species like koalas, Tasmanian devils, northern hairy-nosed wombats and Leadbeater's possums.”
While marsupials are also found in the Americas and Papua New Guinea, around 200 species are native to the Australian continent. And this continent has the world's highest rate of extinction for mammals in general, having lost some 35% of its unique biodiversity since the 1500s. And the country's iconic animals – koalas, wombats and kangaroos – are all marsupials.
The experimental IVF process saw embryos produced by intracytoplasmic sperm injection (ICSI), which as the video demonstrates, is a delicate procedure that sees a single sperm injected directly into a mature egg. While the procedure may not seem revolutionary for mammals, marsupials are a different case altogether.
“Because eastern grey kangaroos are overabundant, we collected their eggs and sperm for use as a model to adapt the embryo technologies already applied to domestic animals and humans,” Gambini said. “Access to marsupial tissues is challenging as they are less studied than domestic animals despite being iconic and integral to Australian biodiversity.
“We are now refining techniques to collect, culture and preserve marsupial eggs and sperm. By developing preservation methods, we aim to safeguard the genetic material of these unique and precious animals for future use to ensure their conservation."
In nature, marsupial young are born premature and migrate to a teat within the mother's pouch, where they develop externally. This makes the tiny animals vulnerable because they're so dependent on the adult nursing them. And using IVF to produce an embryo that would ideally allow scientists to safeguard populations of endangered species that had become too fragmented to find mates or be able to produce genetically viable offspring.
“While it’s difficult to provide an exact timeline, with sustained collaboration, funding and continued technical advancements, we are hopeful the birth of a marsupial through IVF could become a reality within a decade," said Gambini. “This success with kangaroo embryos is deeply fulfilling, representing the culmination of years of training, research and collaboration.”
So while it might be one small hop for kangaroos, it's one potentially giant leap for other marsupials on the brink of extinction.
The study was published in the journal Reproductive, Fertility and Development.
Source: The University of Queensland