The northern white rhino, which is one of the most endangered animals on Earth is almost extinct. The drill, a west African primate, is threatened by habitat loss and hunting. Scientists believe stem cells could be used to preserve - or even revive - these endangered species and others like them.

Scientists have produced the first stem cells from endangered species, which is the first step towards ensuring the survival of endangered species through stem cell technology.

Jeanne Loring and her colleagues at the Scripps Research Institute have created stem cells from frozen skin cells of the two such endangered species.

The best way to manage extinction is to preserve species and habitats but that is not always working, Oliver Ryder, director of genetics at the San Diego Zoo and co-leader of the study, said in a statement. Stem Cell technology provides some level of hope that they won't have to become extinct even though they have been completely eliminated from their habitat.

San Diego's Frozen Zoo has skin cells and other tissue samples from more than 800 species.

Five years ago, Ryder contacted Loring about the possibility of using the samples from the Frozen Zoo to generate and store stem cells.

Around 1972, conservationists in San Diego began freezing skin samples from endangered species, hoping that science would find a way to use these cells and prevent species of going extinct, according to a MIT Technology Review report.

BBC reported that the stem cells were made from skin by a process of re-programming, where retroviruses and other tools of modern cell biology are used to restore the cells to an earlier development stage.

At this stage they are said to be pluripotent, meaning they can be induced to form different kinds of specialized cell such as neurons and cartilage.

Studies using the stem cell approach are in progress to cure human diseases. However scientists hope to be able to use stem cells to create eggs and sperm, which could be then used for breeding and boosting the genetic diversity of endangered species.

Frozen skin cells from threatened as well as extinct species obtained from the Frozen Zoo could be used as a starter kit for new life the Agence France-Presse reported.

Either induced sperm cells could be combined with the eggs from living animals through in vitro fertilization or both eggs and sperms might be generated from stem cells and the resulting embryos could be planted in live host animals.

Scientists believe that this technique would be much more reliable than cloning techniques where the frequency of success is very low, Loring said.

I think that work would be a lot easier ethically with endangered species than with humans, Loring said.

About the two animals in the study:

- The northern white rhinoceros (Ceratotherium simum cottoni) is a highly endangered species with only seven specimens remaining in existence. All seven are in captivity with two in San Diego.

- The drill (Mandrillus leucophaeus) is closely related to the baboons and even more closely to the mandrill. Drills are found only in Cross River State, Nigeria; South Western Cameroon; and on Bioko Island, part of Equatorial Guinea. Drills are among Africa's most endangered mammals, and are listed by the IUCN  (International Union for the Conservation of Nature) as the highest conservation priority of all African primates. Drill numbers have been declining in all known habitat areas for decades as a result of illegal commercial hunting, habitat destruction, and human development.