With chimps 99% genetically identical to humans, you might wonder if the difference between man and ape is all in the head. But chimpanzees are strikingly different from humans in their resistance to devastating diseases, such as AIDS and malaria. For this very reason, Ajit Varki (University of California, San Diego) makes an urgent case to launch a Chimpanzee Genome Project, in a commentary published this month in Genome Research.
As explained in Varki's commentary, diseases that kill humans in large numbers barely cause a ripple in the lives of great apes. Most strikingly, chimpanzees infected with the HIV virus do not get AIDS; instead, the virus lives in peaceful symbiosis with the chimp immune system. Less commonly known is that chimps do not develop Alzheimer's disease, despite sharing a gene that is a high risk for Alzheimer's in humans. In addition, cancers such as breast, lung, and prostate tumors are apparently rare in apes, occuring in less than 2% compared to more than 20% in humans. The list goes on, says Varki, even to teen acne, and in many cases the differences appear to be genetic. The similarity between chimps and humans makes it all the more likely we can identify – and learn from - these genetic differences.
Thus, says Varki, we have a biomedical imperative to embark on a chimp sequencing project. As an added incentive, sequencing the chimp genome should provide us with intriguing glimpses into the nature of "human-ness," that is, what propelled our evolution from our ape-like ancestors. Finally, a chimp project may help us provide better treatment for the thousands of captive apes and their wild relatives threatened with extinction.
Note: Varki's commentary includes a box explaining the oft-quoted "1% difference" between chimp and human genomes.
Contact (Author):
Ajit Varki
Department of Medicine
University of California, San Diego
La Jolla, CA 92037
USA
email: avarki@ucsd.edu
Genome Research