Scientists untangle the evolutionary history of the world’s most common STI
Source: www.iflscience.com Author: Rosie McCall Scientists have analyzed the genomes of viruses to reveal the surprisingly complex evolutionary past of the human papillomavirus (HPV), exposing the salacious details of our ancestors' sexual history in the process. HPV comes in several flavors but HPV16 is the most common subtype worldwide – and it is the one most frequently identified in cervical cancer. Together HPV16 and HPV18 are responsible for 70 percent of all cases, accord to stats from the World Health Organization (WHO). The problem is, it isn't exactly clear how HPV strains contribute to cervical cancer (and other types, including cancer of the anus, the throat, the base of the tongue, and the tonsils). Or why the virus naturally clears in some people but not others. Researchers hope that studying the evolution of the virus will expose biological insights and point at mechanisms that might explain how cervical cancer develops. To try to untangle HPV16's thorny evolutionary past, scientists led by the Chinese University of Hong Kong isolated and examined oral, perianal, and genital samples in 10 adult female squirrel monkeys (Saimiri sciureus) and eight adult rhesus monkeys (Macaca mulatta), half of whom were male and half of whom were female. They found that the virus strains with most in common came from the same part of the body – meaning the oral samples from the squirrel monkeys and rhesus monkeys had more in common than oral and genital samples from the same species, for example. This, the authors say, [...]