A frozen zoo is a storage facility in which genetic materials taken from animals are stored at very low temperatures in tanks of liquid nitrogen. Material preserved in this way can be stored indefinitely and used for artificial insemination, in vitro fertilisation, embryo transfer, and cloning. Some facilities also collect and cryopreserve plant material.
Frozen Zoo® is the largest and most diverse collection of its kind in the world. It contains over 10,000 living cell cultures, oocytes, sperm, and embryos representing nearly 1,000 taxa, including one extinct species, the po’ouli.
he irreplaceable living cell lines, gametes, and embryos stored in the Frozen Zoo® provide an invaluable resource for conservation, assisted reproduction, evolutionary biology, and wildlife medicine.
Germplasm stored in the Frozen Zoo® has the potential to produce offspring when used for in vitro oocyte maturation and fertilization, artificial insemination, and embryo transfer. Successful artificial insemination of cryopreserved sperm has produced chicks of several pheasant species, and frozen cat oocytes have been matured and fertilized in vitro to form advanced stage embryos. Using methods developed in the domestic cat model, thawed cheetah sperm has fertilized an in vitro matured cheetah oocyte, which then developed into an embryo. With intracytoplasmic sperm injection, southern white rhino oocytes were fertilized with sperm frozen for 20 years.
Currently, it is using the Frozen Zoo® to develop a bank of reference barcode samples for the identification of illegal primate and duiker specimens associated with the bushmeat trade. To help guide reintroduction efforts for the critically endangered Przewalski’s horse, our scientists have partnered with others to compare the genetic make-up of samples in the Frozen Zoo® with ancient DNA samples extracted from museum skins in the Russian Academy of Sciences.
Whole genome sequencing projects for African elephants, two-toed sloths, and gorillas have all benefitted from the Frozen Zoo®. An exciting initiative, Genome 10K, is underway to sequence the genomes of 10,000 species in order to provide a new framework for biological inquiry. This worldwide effort will facilitate advances in our understanding of the biology of endangered species that will directly aid in their conservation and management in the wild.
The Frozen Zoo® constitutes a crucial resource for facilitating advances in genetic and reproductive technologies for population sustainability. In a new collaboration with The Scripps Research Institute, our Reproductive Sciences and Conservation Genetics teams are using the resources of the Frozen Zoo® to study the potential for emerging stem cell technologies to rescue the northern white rhino from the brink of extinction.
Their vision for the future is to develop an international network of cryobanks under the umbrella of a Global Wildlife Biobank that is dedicated to sharing resources and expertise and growing a worldwide legacy of irreplaceable reproductive and genetic material that can be used in support of species conservation.