As the frog populations around the world begin to decline, researchers have identified certain genes that may be able to help amphibians develop a resistance to the harmful bacteria and disease that is leading to their decline.
Through research into the genes that are involved in encoding the major histocompatibility (MHC) complex, a large genomic region that plays an important role in the immune system, autoimmunity and reproductive success, it appears these genes have an effect on how resist a frog is to infection by a particular bacterium that is generally associated with the current frog population declines in the wild.
It is thought that by harnessing the power of these genes involved in encoding the major histocompatibility complex and by further maintaining or enhancing the diversity in MHC genes this may offer, at least in the short term, the best hope at safeguarding frog populations in the wild and reducing the threat many species face from extinction.
Through studies that involved exposing African clawed frog tadpoles (which were chosen for their well characterised immune system which is believed will lead to results that are applicable for all amphibians) to several doses of the bacterium Aeromonas hyrdopilia, which is known to cause disease in both fish and amphibians, it was clear that certain genes allowed the tadpoles to survive the bacterial infection but at the cost of some individuals developing more slowly. Among those tested, the patterns of disease resistance corresponded to the tadpoles’ MHC genes rather than other genes that they shared, demonstrating that the MHC genes conferred immunity to certain diseases.
Due to this discovery and the falling populations, many programs are now underway to rescue frogs from declining wild populations and breed them in captivity to ensure that species are not lost to extinction. In addition to this the study suggests that selective breeding of individuals with known disease resistance genes may produce frogs that can survive infection by disease even when reintroduced into the wild, which it is hoped can stem the rapid decline of frog populations in the wild for many years to come.
Original Article:
http://www.sciencedaily.com/releases/2008/07/080715204750.htm
Additional Information:
http://en.wikipedia.org/wiki/Major_histocompatibility_complex
By 42061065
