CRYOBANKING ADVANCES

This is not a moan about our financial institutions as it might sound, even if such matters cause an inward chill or shudder which is one metaphorical meaning of the ancient Greek word κρύος from which the prefix “cryo” is derived. It means icy cold and in biology usually refers to the long-term preservation of organic material, particularly seeds, DNA, blood, sperm, oocytes, embryos, stem cells and tissues of one kind or another. Collectively this is often referred to as cryobanking and the assemblages that are held in specialist repositories around the world holding material for use in reproductive biology, or even the putative resurrection of extinct species, are known as GRBs (genome resource banks). Extensive resources of the greatest possible variety of genomic material are essential when we consider that so many endangered species now only exist in small, isolated populations at risk of negative effects from inbreeding. Seed banks for the plant world are now well-established, examples being the Millennium Seed Bank at Kew in London and the Global Seed Vault on Svalbard on the Norwegian island of Spitsbergen in the Arctic Svalbard archipelago, which aim to preserve the world’s plant genetic resources for the future in ways that retain their viability.

For animals, this branch of conservation science has arisen from early work in the 1940s to preserve semen for artificial insemination. It could enable us to repopulate habitats with species that have died out or been exterminated, thus restoring endangered or perhaps even extinct species, restoring biodiversity. Much progress has been made but this is a scientific frontier and there are significant issues to resolve. An early problem in semen preservation was how to protect the cells from damage during the freezing process, fortuitously but accidentally resolved by the addition of glycerol^[1]. Now we understand much more but viability problems remain and there are many variations between species that make cryopreservation and particularly the use of cryopreserved material in regenerative conservation challenging. For example, the detailed reproductive biology of the females and endocrinology of wild mammals, fish, herpetofauna and birds are often obscure, yet are critical in terms of fertilisation using cryopreserved semen. Much research is needed. (Please note you misguided politicians and Brexit supporters who want to disconnect us from EU environmental science!)

Nonetheless, there are already success stories, the giant panda we all know and love being one of them: application of this and related biotechnology and research has resulted in the status of the giant panda Ailuropoda melanoleuca David, 1869 in China being improved from “endangered” to “vulnerable”. Other examples are the American black-footed ferret Mustela nigripes (Audubon & Bachman, 1851) and Baxter’s or Wyoming toad Anaxyrus baxteri (Porter, 1968). The Frozen Zoo in San Diego is believed to be the world’s largest collection of reproductive cells and tissue collected from wild species.

^[1] There is an interesting article about all this in the Royal Society of Biology’s journal The Biologist 64(4) pages 16–21.

The giant panda is one of the species that has benefited from this reproductive biotechnology. Photo by J. Patrick Fischer [Creative Commons licence CC BY-SA 3.0 (https://creativecommons.org/licenses/by-sa/3.0)].

Thus we enter the realm of resurrection biology, for example of the woolly mammoth of which much has been discussed in the scientific and popular press, but that will have to wait for another news item.

Betts Ecology do all we can to conserve and enhance biodiversity. We do not extend to our own cryobanking (and we don’t have any giant pandas!) but we always alert the relevant institutions to rare and notable species we find, allowing seeds and other material to be collected by their specialists if they require.

Text © Betts Ecology