Investigating the use of germ cell transplantation as an insurance tool for the conservation of the endangered Maugean Skate Zearaja maugeana

Supervisory Team:

Primary supervisor: Jayson Semmens

Co-supervisor: David Moreno

Additional supervisors: Jawahar Patil

Brief project description:

Emergency measures are urgently needed to preserve the valuable genetic resources of endangered fish species. Previously, captive breeding has been the only available option for conserving species, however, replicating the circumstances needed for reproduction is notoriously difficult in captivity. In recent decades, germ cell transplantation has emerged as a novel method for fish conservation (e.g., Yoshizaki & Lee 2018, Stem Cell Res 29:103-110; de Siqueira-Silva et al. 2018, Fish Physiol Biochem 44(6):1469–1485). During germ cell transplantation, a closely related and abundant recipient species is used as a surrogate and injected with germ cells from the testis of the endangered donor species. Those donor germ cells will differentiate and then mature to become either functional sperm or eggs, depending on the sex of the recipient. Importantly, the harvested germ cells can be permanently preserved in liquid nitrogen (cryo-preserved), allowing for cryobanks of cells from endangered species to be created (Lee et al. 2013, PNAS 10(5): 1640-1645). Therefore, simply by mating male and female recipients, an endangered or even extinct species could be regenerated solely from frozen genetic material.

Although germ cell transplantation has been found to be viable for a wide range of fish species, it has never been used for an elasmobranch species. This project aims to investigate if germ cell transplantation has potential for providing an additional tool for aiding elasmobranch conservation, thus addressing one of the biggest marine conservation issues the world currently faces. Our focus species will be the Maugean Skate Zearaja maugeana, which is listed as endangered under the Threatened Species Protection Act (Tasmania), the Environmental Protection and Biodiversity Conservation Act (Australian Commonwealth) and the IUCN Red List.

Skills students will develop during this research project:

The student will learn experimental planning, animal handling, cutting edge germ cell transplantation and cryopreservation techniques, microscope technique, conservation surrogacy theory, animal ethics training and scientific writing training.

Authorised by the Executive Director, Institute for Marine and Antarctic Studies
December 13, 2021