Problems in Developing a Gene Bank for Endangered Species. Does the Human Race Even Care?
Ian M. Gunn
The last Bilby, the last Tasmanian Devil, the last butterfly, the last Dingo--GONE.
Introduction: Goals and Objectives of Gene Banks (GB's)
Biodiversity is seen as a total (and irreducible) part of all life. The complex interaction and balance of the variety of species is seen as essential to maintain a viable and healthy ecosystem. It is believed that the loss of biodiversity will result in a dead and sterile planet that local or regional ecosystems will collapse, that resources will be depleted and that we will become a monoculture of humans with a threat to our own survival.
We know that our lives are supported by the wonderful biodiversity of plants, animals and microorganisms that exist on our planet. But we sometimes forget, particularly when we live in cities, just how important biodiversity is for our happiness and for our lives.
The world is currently losing species at between 1,000 and 10,000 times the rate that occurred before our ancestors first appeared on Earth. Judging from the fossil records, the average lifespan of a species is about 4 million years, which calculates at about four species a year becoming extinct. At a moderate estimation, we are now likely to lose 50,000 species a year over the next decade. Of the 40 mammal species known to have become extinct in the world over the last 200 years, almost half have been in Australia. Theconservation of Earth's biodiversity and the animal species is of paramount importance for the future of the planet's environment. It is becoming increasingly clear that the conservation of natural habitats and the management of captive populations in native reserves, national parks and zoos cannot alone prevent this loss. As the overwhelming loss of species continues in the face of tremendous conservation efforts to preserve habitats and save these species, it is equally important to preserve the genetic resource of these endangered wild species. The creation of genetic resource facilities and banks will enable these genetic resources to be preserved, conserving the genetic diversity of remnant populations, their viability and hopefully the species.
Recent advances in assisted reproductive technology (ART), cryopreservation of cells and tissues and emerging molecular cell biology techniques offer means whereby genetic resources represented by these species can be saved for future generations.
There is an urgent need to establish national and international GB's to save and preserve the rare and valuable genetics both from wildlife (mammals, amphibians, birds, carnivores, fish and reptiles etc.), rare and valuable domestic species (cattle, sheep, pigs, poultry, fish etc.) and specific animal species designed for research programs (rats, mice, rabbits, monkeys etc.).
What are GB's?
GB's are defined as the systematic and organized collection, processing and storage of biological material for future use. These resources comprise samples of semen, testes, embryos, oocytes, ovaries, body tissue, fluid, cell lines and stem cells collected from both live and dead individuals.
The establishment of GB's offer many potential benefits to store and use significant numbers of genomes from single or several species for use in maintaining genetic diversity, to assist in the genetic management of dispersed or fragmented populations of species, and to act as safe national or international facility for collected resources. GB's act as custodians of materials on behalf of individuals, institutions, zoos and conservation organizations and are the custodian of the biological samples for the owners.
Genetic resource samples are stored and preserved through a range of techniques and procedures. These include freezing the samples in a range of protective media at varying temperatures, or the storage of DNA in simple protective storage systems. The samples can be stored indefinitely before being retrieved for transfer or future use in assisted reproductive technology, research, disease investigations or DNA studies.
The cryobanking and future use of genetic samples in ongoing breeding programs may provide an insurance policy against both further loss of diversity and loss of species facing extinction.
It is important to appreciate that while today it's possible to collect and store genetic resources, the technology to successfully use the range of samples lies well into the future. We argue that, unless we instigate national GB's and commence the preservation of genetic resources today, the material necessary to save or recreate species in the distant future, will be lost.
Australia's Gene Bank
The Animal Gene Storage and Resource Centre of Australia (AGSRCA) was established in 1995 as a joint venture between the Monash Institute of Reproduction and Development, Monash University and the Zoological Parks Board of NSW (which includes Taronga Zoo at Sydney and the Western Plains Zoo at Dubbo). Its objective was to develop a national facility for the collection and preservation of genetic resources from rare and endangered animal species. The AGSRCA has established a cryopreservation facility, at Monash University in Melbourne and holds over 100 different species, and in some cases, a wide range of individuals within each species. Examples of some of the target species that the AGSRCA is focusing on include the Northern Hairy-nosed Wombat (Lasiorhinus krefftii), Greater Bilby (Macrotis lagotis) and the Black Rhinoceros (Diceros bicornis michaeli), a number of rare domestic species of pigs, cattle and horses, and an increasing reserve of native Australian fish species
Historic Development of Gene Banks
Historically, the revolution in domestic animal breeding technology over the last 50 years commenced with the collection, preservation and artificial use of semen collected from livestock, particularly in dairy cattle. The success of artificial breeding using frozen semen, embryo transfer procedures and now the advent of cloning in domestic species has underpinned the international establishment of Gene Banks for cattle, sheep, goats, fish, dogs and horses. A classic example of the development of these gene banks was the establishment of the first Australian Canine gene bank in 1976 with the collection and freezing of semen from domestic stud breeding dogs. This bank expanded over the years to include semen from selected and proven working Australian sheep and cattle dogs, guard dogs and guide dogs for the visually impaired. The final progression has been the extension of the bank to include species of wildlife with the collection and storing of semen from the Australian Dingo.
New advances in assisted reproductive technology have proven that genetic resources can be reliably salvaged from the testes and ovaries of recently dead animals for breeding of viable offspring . Further advances are now being developed which open access to using tissue samples from both live and dead individuals by culturing cell lines, i.e., fibroblasts and cumulus cells which could potentially be used for nuclear transfer or cloning in the future. At the very least, it is appropriate to consider the cryopreservation of somatic cells from rare and endangered animals as an alternative to limiting collections to reproductive samples. The cryobanking of genetic material through cell culture lines may provide an alternative to the difficulties of the successfully collection and preservation of gametes of some species (kangaroo sperm, fish embryos) although currently the common specimens stored in GB's include; semen/testes and embryos/oocytes/ovaries.
Constraints and Problems in Developing and Operating Gene Banks for Wildlife
The establishment and on-going operations of wildlife gene banks in Australia has encountered constraints and problems that have been reflected internationally.
These relate to:
Lack of financial support by governments, institutes and the public to establish and maintain gene banks.
Lack of a commitment or interest in the preservation of genetic resources by zoological parks, conservation organizations and species recovery groups to support the collection and delivery of salvaged or opportune collected genetic resources to a GB.
Fear and hence lack of peer support, because of critical competition for conservation funds from those committed to wildlife habitat protection or restoration.
The problems related to defining the ownership of the wildlife and the samples of their genetic resources--is it Federal or State Government, zoological parks etc.?
Knowing who sets the priorities for which species are targeted for collection and storing of genetic samples? Which species have the greatest potential for future recovery or which are the last members of a rare exotic species?
The risks of spreading or introducing disease via gene banks to material susceptible populations in different regions or between island populations.
The limitations in demonstrating that the wildlife genetic resources stored in GB's can be successfully utilized in assisted breeding programs--AI, embryo transfer or cloning.
Public Interest and Commitment
While 5-10% of the population appear to understand and support the concepts and operations of GB's, the majority appear to have no understanding or interest in there operation to assist in the long term conservation of our endangered wildlife. 'If it's not in my backyard it's not my responsibility', is the common attitude.
A significant component of public feeling is fatalistic attitude which goes something like this 'due to the expansion and demands of the human race and its desire for survival, the loss of our wildlife is inevitable. Why attempt to prevent this so-called "evolution" that is occurring across the world today? Anyway, I can go to the local zoo or to my living room watch Planet Earth or Discovery to see these animals. I'll never see them in the wild, so what.'
The utilization and over exploitation of biodiversity is a hallmark of human activity today. The attitude is that this natural resource should be used for the benefit of the current generation with no regard to their preservation for future generations. This is in contrast to our indigenous human population, who see themselves as caretakers or custodians of the land and its resources.
There are situations that have generated wide public interest and support but in the main these have been restricted to the preservation of high profile exotic mammalian species such as the Black Rhino, the African Gorilla and the Chinese Panda; or to species that offer a potential benefit to the health and welfare of humans, such as macropod milk with its antibiotic properties.
Justification and Benefits
It is important to examine and evaluate the perceived benefits of a national wildlife GB. These include:
The preservation of the regions diverse genetic diversity in the face of the rapid and continuing loss of wildlife species.
The creation of an insurance bank of genetic material as a reserve to supplement captive breeding recovery programs and to maintain genetic diversity in fragmented wild populations.
A major reserve of DNA for determining the information on population structure and evolution of extinct, endangered or vulnerable species.
A source of samples for retrospective investigations into disease outbreaks or mutational changes.
The Future for GB's
Regional or species specific wildlife gene banks have been in existence for over 20 years. Australia initiated the establishment of the first national GB in 1995 and this has been followed by similar banks in Africa, America and now The Frozen Ark Project in the UK who's goal is to link wildlife banks around the world into a international network.
GB's are not only a substitute for captive breeding programs or to fulfill the need to preserve our wildlife in its natural habitat. They are also an insurance for the future and a valuable reserve of information to supplement or complement the breeding and survival of our wildlife whether in captivity or in mainland island populations in the wild.
Education and media promotion is highlighting the critical importance of our biodiversity and the role of scientific advances in assisting this cause. GB's are an essential component of this program and their ability to expand and develop will aid in saving our resources for future generations.
"The natural world offers myriad forms of value in education, exploration, aesthetic experience and irreplaceable products and services" E.O. Wilson
I wish to acknowledge comments, suggestions and references from Ann Clarke, Oliver Ryder , Cathi Lehn, Peter Raven and Colin Tudge.