Gui Haiyan (1st L) from Guangzhou KingMed Diagnostics Group Co., Ltd. conducts detections at the clinical laboratory of the Leishenshan (Thunder God Mountain) Hospital in Wuhan, central China's Hubei Province, March 4, 2020. (Xinhua/Cheng Min)

New research into the characteristics of a recently identified bat coronavirus, the novel coronavirus's closest relative, shows the insertion of multiple amino acids in a similar manner to the coronavirus, suggesting that seemingly unusual insertion events can occur naturally in coronavirus evolution. 

The research paper, titled "a novel bat coronavirus closely related to SARS-CoV-2 contains natural insertions at the S1/S2 cleavage site of the spike protein," was recently published on the website of Current Biology, a biweekly scientific journal. 

The paper was jointly written by international scientists from the University of Shandong, Xishuangbanna Tropical Botanical Garden in South China's Yunnan Province and the University of Sydney.

Although bats are thought to be the most likely natural hosts for novel coronavirus, the origins of the virus remain unclear. The scientists found a novel bat-derived coronavirus, identified from samples from 227 bats collected from Yunnan Province between May and October 2019, which shares 93 percent nucleotide identity with the SARS-CoV-2, or novel coronavirus, at the scale of the complete virus genome, and is the closest relative of the novel coronavirus reported to date, according to the paper. 

The newly found coronavirus was characterized by the insertion of multiple amino acids at the junction site of the S1 and S2 subunits of the spike protein in a similar manner to the SARS-CoV-2. This provides strong evidence that such insertion events can occur only naturally in animal betacoronaviruses, the paper said.

Some Western countries and politicians have repeatedly spread rumors that the virus was leaked from the Wuhan Institute of Virology and claimed "it was a man-made virus," despite global scientists and the World Health Organization have reiterated that the novel coronavirus is "natural in origin."

Global Times