The Chinese team found the new bat coronavirus, which confirmed that the new coronavirus originated in nature!

A new coronavirus was found in bat samples collected in Mengla County, Yunnan Province last year. The virus shared 97.2% identity with the new coronavirus (sars-cov-2) in the longest coding gene region 1ab.at the same time, the research team also found three PAA residues inserted at the junction of S1 and S2 of S protein (spike glycoprotein) in this new coronavirus. Therefore, they believed that the tetraamino acid insertion of sars-cov-2 at the junction of S1 and S2 was not "artificial trace", which strongly proved that it originated from nature.on May 10, local time, current biology, a subsidiary Journal of cell, published online "a new bat coronavirus closed related to sars-cov-2 contains natural insertions at the S1 / S2 cleavage site of the spike protein ”Researchers from Shandong First Medical University, laboratory of etiology and epidemiology of emerging infectious diseases in Colleges and universities of Shandong Province, Xishuangbanna Tropical Botanical Garden of Chinese Academy of Sciences, Beijing Institute of life sciences, Chinese Academy of Sciences, Wuhan Institute of virus, Chinese Academy of Sciences, Institute of Microbiology, University of Sydney, Australia, made the above conclusions.in this paper, the team reported a new bat derived coronavirus, rmyn02, which was identified from genome analysis of 227 bats collected from Yunnan Province, China, between May and October 2019.studies showed that novel coronavirus SARS-CoV-2 and RmYN02 had a homology of 93.3% in the whole virus genome, and the homology of the 1ab gene closest to SARS-CoV-2 was 97.2%.in contrast, rmyn02 receptor binding domain (RBD) showed low sequence homology (61.3%) with sars-cov-2, which may not bind to angiotensin converting enzyme 2 (ACE2). However, similar to sars-cov-2, rmyn02 is characterized by multiple amino acid insertions at the S1 and S2 subunits of S protein.according to the team, this is a strong proof that such insertion events can occur in nature.these data suggest that sars-cov-2 originated from multiple natural recombination of viruses present in bats and other wild animals.the corresponding authors of this paper are Shi Weifeng, director of Institute of pathogenic biology, School of basic medicine, Shandong First Medical University, director of etiology and epidemiology Laboratory of emerging infectious diseases in Shandong Province; bi Yuhai, leader of virus transmission early warning and pathogenesis research group and project researcher of Institute of microbiology, Chinese Academy of Sciences; comprehensive protection of Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences Alice Catherine Hughes, leader and associate professor of landscape ecology group of the center.the study was previously published on the preprint website biorxiv on March 5 local time.the origin of the new coronavirus is still unclear. There are still a large number of coronavirus sars-cov-2 in wild animals, which has caused an unprecedented epidemic of pneumonia in China and other regions, which has aroused public health attention worldwide.although bats are considered to be the most likely natural hosts of sars-cov-2, the origin of the virus remains unclear. Novel coronavirus is different from SARS-CoV and MERS-CoV by phylogenetic analysis of. SARS-CoV-2 is a new type of coronavirus.so far, the virus most closely related to sars-cov-2 is ratg13, which was isolated from a Chinese chrysanthemum bat specimen collected in Yunnan Province by Shi Zhengli team of Wuhan Institute of virus, Chinese Academy of Sciences in 2013. There were 96.1% nucleotide homology and 92.9% s gene homology between ratg13 and NCV.these data again indicate that bats are important hosts of coronavirus.however, it is worth noting that Professor Guan Yi of the State Key Laboratory of emerging infectious diseases, School of public health, University of Hong Kong, Professor Hu Yanling of Guangxi Medical University, and Professor Shen Yongyi and Professor Xiao Lihua of South China Agricultural University and Lingnan Modern Agricultural Science and technology Guangdong Laboratory have previously reported sars-cov-2 in Malay pangolins Related to the coronavirus, these pangolins were illegally smuggled into Guangxi and Guangdong.the team noted that although the coronaviruses detected in these pangolins were further away from sars-cov-2 at the genome-wide level than ratg13 and sars-cov-2, they were very similar to sars-cov-2 in the receptor binding domain (RBD) of S protein. therefore, although it is not clear whether pangolins are intermediate hosts of sars-cov-2 transmission to humans, they may play an important role in the ecology and evolution of coronavirus. they believe that these viruses found in pangolin can indicate that there are still a large number of coronavirus samples in wild animals, some of which may be directly involved in the emergence of sars-cov-2. a new bat derived coronavirus, named rmyn02, is reported in the paper. From May to October 2019, the team collected 302 samples from 227 bats in Mengla County, Yunnan Province. these bats belong to 20 different species. Most of the samples were obtained from Rhinolophus malayanus (n = 48,21.1%), Hipposideros larvatus (n = 41,18.1%) and Rhinolophus stheno (n = 39,17.2%). the samples were obtained from a variety of tissues, including pterygium (219), lung (2), liver (3) and feces (78). except for 3 bats, all bats were sampled and released while alive. using a new generation of metagenome sequencing technology, the research team first identified two preliminary consensus sequences. the samples produced by these sequences were collected from 11 feces collected from the period from May 6 to July 30, 2019. after a series of validation steps, the team obtained a partial (23395bp) and a complete (29671bp) genome sequence of bat coronavirus, named betacov / RM / Yunnan / yn01 / 2019 (rmyn01) and betacov / RM / Yunnan / yn02 / 2019 (rmyn02). in contrast, rmyn02 is closely related to sars-cov-2, showing 93.3% nucleotide sequence identity, but ratg13 and sars-cov-2 have a higher identity (96.1%) at the whole genome level. rmyn02 and sars-cov-2 are very similar in most genomic regions (e.g., 1ab, 3a, e, 6, 7a, N and 10) & gt; 96% sequence identity). In particular, rmyn02 had 97.2% identity with sars-cov-2 in the longest coding region 1ab (n = 21285). however, the sequence identity of rmyn02 and sars-cov-2 in S gene (nucleotide 71.8%, amino acid 72.9%) was much lower than 97.4% between ratg13 and sars-cov-2. it is also worth noting that rmyn02 and sars-cov-2 share only 62.4% amino acid identity in RBD. The amino acid homology between pangolin coronavirus and sars-cov-2 from Guangdong Province was 97.4%, which was the closest to sars-cov-2 in RBD region. the results of homologous model, in vitro experiment and three-dimensional structure analysis of S protein around sars-cov-2 showed that sars-cov-2 could also use ACE2 as cell receptor. the team also used homologous models to analyze RBD of rmyn02, ratg13 and two pangolin CoVs. it was found that the amino acid deletion in rmyn02 RBD formed two rings shorter than sars-cov-2 RBD near the receptor binding site. importantly, the conserved disulfide bonds in the external subdomain of SARS CoV, sars-cov-2, ratg13, pangolin / mp789 / 2019, pangolin / GX / p5l / 2017 are missing in rmyn02. the team speculated that these deletions may lead to conformational changes, thereby reducing the binding of rmyn02 RBD with ACE2, or even leading to non binding. of course, it is also possible that the ring deleted SARS associated coronaviruses, including rmyn02, zxc21 and zc45, use an unknown receptor. it is worth mentioning that six amino acid residues (l455, f486, q493, s494, n501 and y505) in RBD are the main determinants of the binding of sars-cov-2 to ACE2 receptor. consistent with homologous modeling, pangolin / mp789 / 2019 had the same amino acid residues as sars-cov-2 at all six sites. in contrast, ratg13, rmyn02, rmyn01 and sars-cov-2 all had the same amino acid residues at one site. the team believes that this evolutionary pattern is a complex combination of recombination and natural selection. the team also conducted phylogenetic analysis of bat coronavirus in rmyn02, ratg13, sars-cov-2 and pangolin. consistent with previous studies, two subtypes of pangolin beta CoVs were formed. however, whether pangolins are natural reservoirs of these viruses, or whether they are isolated from bats or other wild animals, needs further verification. it is more noteworthy that rmyn02 has the closest genetic relationship with sars-cov-2 in most viral genomes, although there is still a long branching distance between the two viruses. s gene tree showed that sars-cov-2 was close to ratg13 and far away from rmyn02, indicating that the latter had undergone recombination in S gene. in the phylogenetic tree of RBD, sars-cov-2 and pangolin cov / Gd were most closely related to each other, and they were far away from bat virus, indicating that recombination took place again. finally, complete RNA dependent RNA polymerase (RdRp) gene (often used in RNA virus phylogenetic analysis) phylogenetic analysis showed that rmyn02, ratg13 and sars-cov-2 formed a completely different subgroup from that of pangolin virus. sars-cov-2 is a natural origin. It is possible to obtain the hemagglutinin (HA) protein of avian influenza virus (aivs) by recombination. The S protein of coronavirus divides into two subunits S1 and S2. However, insertion of polybasic amino acids into the cleavage sites of some AIV subtypes is considered to be associated with enhanced pathogenicity. it is worth noting that one of the characteristics of sars-cov-2 is the insertion of a tetraamino acid at the junction of S1 and S2, which has not been observed in other β - coronavirus lineages. the insertion of the cleavage site, known as Flynn protease, is unique to sars-cov-2 and has been found in all detected sars-cov-2 sequences. the team also found three PAA residues inserted at the junction of S1 and S2 in rmyn02, which they think is very important. "although the inserted residues (and the resulting nucleotides) of sars-cov-2 are different from those in rmyn02, it can be concluded that they are an independent insertion event. Their presence in wild animals (bats) strongly indicates that they are of natural origin and may be obtained by recombination. Therefore, these data strongly indicate the natural origin of sars-cov-2. in addition, the team once again determined that the bat host of rmyn02 is Rhinolophus malayanus, which is 100% consistent with the sequence obtained from a species of Rhinolophus malayanus (GenBank access mk900703). both the Malay and the Chinese are widely distributed in Southwest China and Southeast Asia. it is mentioned in the paper that in general, these bats do not migrate over long distances and are very gregarious. They are likely to live in the same cave, which may promote the occurrence of virus exchange and recombination between them. it is worth noting that ratg13 was found in anal swabs and rmyn02 was found in feces. therefore, feces are one of the bats that transmit the virus to other animals, especially those that can take advantage of the cave environmentTips: never lose hair first... 10. Change sperm speed, can affect the sex of offspring?