How Gene Banks Work

If you stop and look at the civilization surrounding you, you're liable to spot some truly amazing sights: aircraft and skyscrapers touching the clouds, power grids and road systems crisscrossing the land and invisible communication networks wrapping up much of the planet. Yet all of our greatest achievements in science, art and philosophy go back to one crucial breakthrough: domestic agriculture. When early humans finally began to abandon the hunting and gathering lifestyle for permanent living and crop cultivation, they finally had the time to devote to much of what we've come to know as human culture.

While early humans depended on a variety of scavenged plant and animal resources, we've since reached the point where massive fields support a single food crop that feeds millions. This puts our food supply in a very delicate situation. What happens if climate change introduces new pests or renders an area inhospitable to a former boom crop? What if disease or natural and man-made disasters wipe it out? By storing the genes behind these crops, we provide ourselves with a backup -- money in the bank, so to speak.

But major cash crops aren't the only species researchers collect in gene banks. Take the common potato for instance. It's not the only spud in the freezer -- researchers store thousands of tubers from different parts of the world to safeguard the french fries and Tater Tots of the future. If a disease comes along that targets a major food species of tuber, perhaps another, lesser-known species will serve as a suitable replacement or contain essential genetic information to engineer a resistant species.

Of course, plants fill our pharmacies as well as our dinner plates. Gene banks allow us to prepare for future unknowns by safeguarding plants that could one day play a crucial role in the development of new medicines. This is just one more reason to safeguard not only plants we use, but also protect global biodiversity by preserving the rest. This includes more than 500 plant species from around the world listed as endangered by the U.S. Fish and Wildlife Service. Who knows what wonder drug is out there right now, undiscovered in an endangered portion of the Amazon rain forest?

The concept of stockpiling plant genes is nothing new. Farmers have stored away seeds to ensure future harvests for thousands of years. Today, seed banks all over the world work to chronicle and store the genetic blueprints for crops, especially those that are vital food crops. Some of these are government-owned, others are operated by private and international organizations. For a detailed look at these operations, read How Seed Banks Work.

Botanists can preserve genetic material in two ways. One method involves drying and freezing the seeds at temperatures more or less on par with a typical winter. Some seeds can survive in this state for decades, but eventually require thawing and regrowing to provide fresh, vital seeds. However, if the seeds are frozen at lower, cryonic temperatures, all molecular motion comes to a halt. While this second method is far more expensive than normal freezing, it vastly increases the shelf life of a plant's genetic material.

Currently more than 1,400 gene banks worldwide store seeds and gene samples from hundreds of different plants [source: Popular Science].

­Bu­t what about the planet's animal life? On the next page, we'll look at some of our efforts to protect endangered animals and resurrect extinct ones.

While seed banks typically prioritize widely grown crop plants, scientists looking to stockpile animal genes focus in a different direction: species on the verge of extinction. If this sounds like a relatively small undertaking, consider that the U.S. Fish and Wildlife Service currently lists more than 900 species as endangered. If current trends continue, scientists predict more than 1,000 species of mammals will face extinction in the next 30 years [source: The Frozen Ark Project].

Several programs are working to preserve the genes of endangered animals. China's Chengdu Research Base of Giant Panda Breeding keeps eggs, sperm and other tissue samples from pandas and other natives species preserved in cold storage. The United Kingdom's Frozen Ark Project has taken on the mission of creating a network of similar gene banks around the world devoted to endangered animals.

Scientists in India have taken the idea a step farther by working to eventually reintroduce the Indian cheetah back in to the wild, more than half a century after it was declared extinct. While the researchers lack cryogenically preserved tissue, they have been able to collect skin and bone tissues from museums and zoos. They hope to fill in the genetic blanks by studying the genes of similar cheetah populations in modern-day Iran.

However, scientists haven't completely overlooked domestic animals. Some gene banks have set out to document and store DNA from major livestock breeds. The United Kingdom's Department of Agriculture and Rural Development founded a semen archive to safeguard the genetic profiles of rams in Great Britain and Northern Ireland.

To preserve genetic information for animals, scientists must cryogenically freeze diverse specimens of sperm, eggs, hair, skin and blood from target species to provide the best chance for future cloning. To achieve this, scientists would use a female from a related species as a surrogate mother. They'd take one of the surrogate's eggs and fuse it with a cell from the animal to be cloned. The mother would, in effect, give birth to another species -- making her a biologic mother, but not a genetic one. For more information about this process, read ­­How Cloning Works.

Would this process work? Scientists have already proven that it can. On Jan. 8, 2001, U.S. scientists announced the birth of a baby gaur, a large endangered ox native to India and Asia. The gaur's mother, however, was a common cow.

The widespread use of this technique to repopulate the planet with extinct and endangered animals is still years away. In the short term, such gene banks allow scientists to study endangered species and learn how best to sustain them in the future.

But what about the species responsible for so many of these near-extinctions? It should come as no surprise that scientists are preserving human genetic materials as well. Sperm banks in which doctors freeze semen for use in artificial insemination serve as a prime example.

Other gene banks, such as Iceland's deCODE project, store human genetic material for medical research. China is currently working to collect and store the genetic data from residents in the city of Taizhau. The researchers have already gathered samples from 10,000 individuals and hope to collect a total of 5 million [source: BBC News].

Steadily, humans are loading their frozen arks. We've hidden them in Norway's icy mountains, buried them in subterranean vaults -- there's even talk of sending gene banks to the moon. Will we one day need these genetic reservoirs to rebuild a planet laid waste by natural or man-made disaster?

­Hopefully, we'll never have to find out. Explore the links on the next page to learn more abo­ut the genetic marvels behind life.