Dr Tullis Matson is a modern-day Noah building an ark to save endangered animals from extinction. His space-age life-raft is full of frozen cells, eggs and sperm, which are stored in suspended animation ready for the day they can be brought back from limbo and used to create new life.
He is one of the pioneers behind a type of technology dubbed cryo-conservation, in which biological samples taken from endangered animals are ‘banked’ to be used in future breeding programmes to re-establish populations of critically endangered or extinct animals.
Dr Maison is the founder and Chair of Nature’s SAFE, one of the only charitable ‘living’ biobanks in the world where samples are stored in a way that enables them to be reanimated and used in a range of different reproductive techniques.
To date Nature’s SAFE has cryo-preserved multiple cell types from many endangered animal species, including the critically endangered mountain chicken frog, Javan green magpie, Humboldt penguin, and jaguar. The 100th species to join biobank, was the Owston’s civet; an animal on the brink of extinction in the wild across South East Asia.
Science that allows frozen animal cells to be used in breeding programmes is already available. The reproductive cells – or gametes – stored indefinitely at Nature’s SAFE can be used in the same way sperm and eggs are currently used in human IVF cycles.
The non-reproductive, or somatic, cells can be used in a reproductive technique called somatic cell nuclear transfer. In this cloning technology, the nucleus of an egg cell is replaced with a nucleus taken from a body cell. Electricity then fuses the egg and nucleus and the cell multiplies, creating an embryo which is transferred to a surrogate mother. This process was used to create the world’s first clone, Dolly the sheep, in 1995.
Since then, cloning has become a routine tool for duplicating farm animals, pets including cats and dogs, and even prized racing camels. Recently, a cloned black-footed ferret was created using skin cells from an animal that had been dead for decades using eggs that were frozen in 1988. The clone was created by one of the world’s only other live cell biobanks, Frozen Zoo, a program of San Diego Zoo Global that has collected samples from some 1,100 rare and endangered species worldwide.
Another nascent technology that could use Nature’s SAFE samples in the future allows scientists to reprogramme cells to stem cell stage, and then grow them as different cells. Using this method, a skin cell can be grown into an egg or sperm. The technique was first successfully recorded by researchers at the Beijing National Stem Cell Bank who reported creating a mouse in 2009 using reprogrammed adult mouse skin cells taken from a live animal.
In July this year researchers in Japan created a cloned mouse from freeze dried skin cells, paving the way for an easier cell storage method.
‘If these cells can be preserved without liquid nitrogen using freeze-drying technology, it allows genetic resources from around the world to be stored cheaply and safely,’ said Prof Teruhiko Wakayama who led the work at the University of Yamanashi in Japan. ‘Developing countries will be able to store their own valuable genetic resources in their own countries.’
But until that happens Tullis’s hunt for endangered samples to store in the high-tech freezers located at Nature’s SAFE facility located on his farm in Shropshire, rural England, remains the main hope many species will have. The charity works with a network of leading reproductive biologists, cryobiologists and breeding management specialists.
It collaborates with organisations such as the European Association of Zoos and Aquaria Biobank, and is the first dedicated cryopreservation hub within their cryopreservation network for European Zoos. When animals in the partner zoos die, cell samples are collected and sent to Nature’s SAFE for storage in the hope that they will be used at some point in the future for breeding programmes.
Nature’s SAFE biobank fundamentally differs from other biobanks because it stores live cells that can be frozen and reactivated. Most biobanks store samples at -80°C in ultra-cold freezers for use in genetic research. Nature’s SAFE cryopreserves live tissues and cells indefinitely in liquid nitrogen at -196°C. When thawed, the samples remain viable living cells, meaning they can be used for reproduction purposes.
The Bigger Picture
Some sceptics argue that cryo-conservation – storing cells to create new life – is a futile endeavour because habitat loss and climate change are the main drivers of wildlife decline and that without sorting these issues out first, reintroduced and revived species will be released into hostile habitats. But Tullis sees the bigger picture.
‘This is the cornerstone of conservation,’ he says. ‘Yes, you can’t put revived species back in the wild if there is no suitable habitat left, but hopefully one day mankind will get its house in order and that problem will be solved. If we took that attitude now – that it is not worth it – we’d never have any animals to bring back because their cells would not have been saved.
‘This is a fail-safe. Like the Millennium Seed Bank for plants, we need a backstop for animals too, a just-in-case. We must start banking now because if we wait for numbers to plummet, we will not have a big enough breeding pool left to take tissue samples from.’
The practice of banking samples during cryo-conservation also helps the future genetic diversity of species where populations are dwindling, which can lead to inbreeding. In mammals, offspring have a set of genetic instructions from each biological parent. If those parents are related, any genetic diseases they have are much more likely to be passed on. Banking cells from a wide range of individuals preserves a wider gene pool.
Before he set off on his mission to resurrect dying species, Tullis was one of the first horse breeders in the UK to introduce artificial insemination. He realised that the same methods could be used for other animals, particularly rare breeds. In 2019 his company, Stallion AI Services, a centre of excellence for equine reproduction and supporter of the Rare Breeds Survival Trust, helped breed a Suffolk Punch, a rare type of horse. There were only a handful of mares left and the company was able to use technology to ensure the resulting foal was a female.
‘It’s the most rewarding thing you can do and the feeling it gives you for doing your bit is just amazing,’ smiles Tullis, whose charity was recently given The Queens Award for Innovation.
In October 2019 Tullis travelled to South Africa where, along with a team of conservationists, he was able to successfully extract a sample for cryo-conservation from a bull elephant, which had been tranquilised. The dramatic operation involved a helicopter, several vehicles and specialist equipment. The elephant was left completely unharmed by the procedure.
He plans to carry out a similar procedure for cryo-conservation with a Northern White Rhino later this year in collaboration with the Rhino Fertility Project at the University of Oxford.
These types of big gamete hunts are rare for Nature’s SAFE, however. The vast majority of the 100 samples the charity had collected so far for cryo-conservation have come from zoos. And because of a cautious interpretation of EU ethics laws, which dictate that you cannot perform procedures on animals if the procedure does not benefit the animal, most of the animals from which the samples were taken had died. Most recently the charity took possession of a sample from a cheetah which had died at Chester Zoo.
Tullis explains: ‘There are different rules around the world. In Europe we can only currently collect samples when an animal passes away as veterinary rules will not allow intervention that doesn’t benefit the animal or the immediate group. Using dead donor animals gives hope when something dies. Although the animal has passed, it may well help the survival of the species in the future.’
The charity has partnerships with zoos and the vets working in them perform the biopsies on animals that die and then store and send the samples to the biobank for cryo-conservation.
‘Ethically we want to make sure that everything is right. Outside Europe the rules on taking small biopsies are different,’ says Tullis.
For Tullis and the team at Nature’s SAFE, time is of the essence. He explains that life on Earth is currently in a mass extinction event, a period of geological time in which a high percentage of biodiversity dies out. There have been five such events, one of which wiped out the dinosaur.
Along with their partner organisations they collect samples whenever they have an opportunity and are also constantly fund-raising to expand their capacity. Donors include corporations and individuals.
‘We are in the 6th mass extinction,’ says Tullis. ‘It is the largest predicted loss of living biodiversity in 65 million years. More than one million of the world’s species are threatened with extinction, largely because of the actions of humanity through a range of factors including climate change, habitat loss, pollution, and poaching. We haven’t got the luxury or the time to pick and choose what samples we want. We take whatever we can get in. Ideally, we would like to do all the critically endangered species first but logistically it doesn’t work like that. Our model is so up-scalable and the return on investment is priceless. It cost £5000 to store a sample and potentially save one species. To me that seems like a very good return on investment.’
The charity’s cryo-conservation work is widely applauded by experts, who agreed that it is essential and timely, considering that mankind has fallen woefully short in its stewardship of the natural world. Two years ago, an important deadline passed. The international community had agreed to put in place a series of measures to protect the diversity of life on Earth by 2020.
Known as the Aichi Biodiversity Targets, these were established by the Convention on Biological Diversity (CBD) in an effort to protect and conserve the biodiversity that underpins global food security, health and clean water.
The convention was signed by 150 government leaders at the 1992 Rio Earth Summit. By the time the deadline was reached, none of these had been met. Reasons for the failure included lack of investment, resources, knowledge, and accountability. Experts say this global failure to get to grips with the bio-crisis illustrates why cryo-conservation of material from our most vulnerable species is vital. It’s a sad irony that without concerted action to reverse the bleak future facing so many important species, one day it is conceivable that one of the vials frozen in Tullis’s bank will be labelled ‘human’.