AsianScientist (Nov. 12, 2018) – Scientists have analyzed the genomes of human papillomaviruses (HPVs) to trace their evolution. They published their findings in PLOS Pathogens.
Epidemiological studies have demonstrated that persistent infection with HPVs is the main cause of cervix pre-cancer and cancer. However, the origin and evolution of cancer-causing HPVs remain poorly understood.
To better understand the molecular evolution of HPV16 and other types of HPVs that cause cancer, researchers at the Chinese University of Hong Kong (CUHK) and the Albert Einstein College of Medicine in the US isolated viruses from primates, performed viral genomic analyses and estimated the divergence times of cancer-causing HPV variants from their most recent common ancestors.
The findings suggest that the first stage of the evolution of cancer-causing papillomaviruses involves niche adaptation of viruses to host ecosystems. The viruses then co-evolved with their primate hosts for at least 40 million years.
Genomic analyses further revealed that HPV16 variants diverged from their most recent common ancestors approximately half a million years ago, roughly coinciding with the timing of the split between archaic Neanderthals and modern Homo sapiens. The findings revealed recent viral sexual transmission from Neanderthals to modern non-African humans through multiple interbreeding events in the past 80,000 years.
According to the authors, understanding the evolution of papillomaviruses should provide important biological insights and suggest mechanisms underlying HPV-induced cervical cancer.
“The evolution of oncogenic HPVs follows a methodical pathway of first adapting to a specific ecologic niche or to anatomic regions of the human body (e.g., the cervix), followed by co-divergence in archaic human ancestors and subsequent selection within specific human genetic backgrounds,” said Assistant Professor Chen Zigui of CUHK. “Moreover, the evolution of HPVs can also provide novel insights about human evolution.”
The article can be found at: Chen et al. (2018) Niche Adaptation and Viral Transmission of Human Papillomaviruses from Archaic Hominins to Modern Humans.
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Source: PLOS; Photo: Shutterstock.
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