Project aims to preserve endangered frogs -- by freezing their sperm

Thousands of amphibian species around the world are in danger of extinction. Now, a new research project funded by the Austrian Science Fund hopes to preserve some of these species by developing better methods to freeze and preserve amphibian sperm. While obviously not as ideal as keeping species alive in the wild, cryopreservation is at least one more tool that could be used to keep amphibian species from dying out.

The goal of the project is to find the best way to freeze and preserve the amphibian sperm. According to project manager Prof. Robert Patzner, eggs can be damaged during freezing, but sperm is hardier and takes up less space. The project will look at various parameters, including "the optimum dilution medium, the concentration of the cryoprotectants used to lower the freezing point of the water in the sperm, the precise freezing rate and details of the subsequent thawing process."

Once thawed, the sperm will be used to fertilize eggs from other species, which have been irradiated to remove their genetic material. A "heat shock" will then inspire the genetic material from the sperm to duplicate, creating androgenesis, or the development of a living being from exclusively paternal chromosomes.