Natural selection in the evolution of SARS-CoV-2 in bats, not humans, created a highly capable human pathogen.

ABSTRACT: RNA viruses are proficient at switching host species, and evolving adaptations to exploit the new host's cells efficiently. Surprisingly, SARS-CoV-2 has apparently required no significant adaptation to humans since the start of the COVID-19 pandemic, with no observed selective sweeps since genome sampling began. Here we assess the types of natural selection taking place in Sarbecoviruses in horseshoe bats versus SARS-CoV-2 evolution in humans. While there is moderate evidence of diversifying positive selection in SARS-CoV-2 in humans, it is limited to the early phase of the pandemic, and purifying selection is much weaker in SARS-CoV-2 than in related bat Sarbecoviruses . In contrast, our analysis detects significant positive episodic diversifying selection acting on the bat virus lineage

SUBMITTER: MacLean OA 

PROVIDER: S-EPMC7302214 | biostudies-literature | 2020 Jul

REPOSITORIES: biostudies-literature