Two relatives close to SARS-CoV-2 are in Japan and Cambodia

2020/11/26 Agirre Ruiz de Arkaute, Aitziber - Elhuyar Zientzia Iturria: Elhuyar aldizkaria

Rhinolophus cornutus bat. Ed. Wikipedia

Evidence so far suggests that SARS-CoV 2 originated from horseshoe bats, but it is unclear whether it was transmitted directly from the bat to the human being or through an intermediate hostel. It seems that it is not a new virus that suddenly appeared. Although we met her in 2019, researchers believe she existed before. In fact, as reported by the journal Nature, samples of long-frozen bats have found two other crowns closely related to SARS-CoV-2. Both, outside China.

One is discovered in a Japanese laboratory, in a Japanese horseshoe bat captured in 2013 (Rhinolophus cornutus). Sequenced by this virus, called Rc-o319, 81% of its genome is equivalent to the SARS-CoV-2 virus. It does not seem, therefore, enough similarity to provide useful information on the origin of the pandemic. The second virus has been found in Cambodia, in two horseshoe bats of Shamel (Rinolophus shameli) caught in 2010. They have not yet sequenced it altogether, but they believe it may be the closest relative to the well-known SARS-CoV-2. Among other things, it is necessary to sequence the protein gene that uses the virus to enter human cells. The result of sequencing will give the measure of kinship, but it should be similar to 99% to be the direct ancestor of the current pandemic virus.

With or without direct ancestors, it seems that in the Rinolophus bats are frequent viruses closely related to SARS-CoV2. China found the RaTG13 virus in a 2013 bat, the closest found so far (96% parity). Now, China will resume the study of frozen bats long ago, looking for more data, as it is believed that there may be more relatives close to SARS-CoV2 in laboratories, still to be discovered. US researchers will investigate frozen bats from laboratories in Laos, Malaysia, Nepal, Thailand and Vietnam, also looking for the direct predecessor of SARS-CoV-2.