We report the isolation and characterization of a novel bat coronavirus which is much closer to the severe acute respiratory syndrome coronavirus (SARS-CoV) in genomic sequence than others previously reported, particularly in its S gene. Cell entry and susceptibility studies indicated that this virus can use ACE2 as a receptor and infect animal and human cell lines. Our results provide further evidence of the bat origin of the SARS-CoV and highlight the likelihood of future bat coronavirus emergence in humans.T he 2002-2003 outbreak of severe acute respiratory syndrome coronavirus (SARS-CoV) was a significant public health threat at the beginning of the 21st century (1). Initial evidences showed that the masked palm civet (Paguma larvata) was the primary suspect in the animal origin of SARS-CoV (2, 3). Later studies suggested that Chinese horseshoe bats are natural reservoirs and that the masked palm civet most likely served as an intermediate amplification host for SARS-CoV (4, 5). From our longitudinal surveillance of bat SARS-like coronavirus (SL-CoV) in a single bat colony of the species Rhinolophus sinicus in Kunming, Yunnan Province, China, we found a high prevalence of diverse SL-CoVs (6). Whole-genome sequence comparison revealed that these SL-CoVs have 78% to 95% nucleotide sequence identities to SARS-CoV, with the major differences located in the spike protein (S) genes and the region of open reading frame 8 (ORF8). We recently isolated a bat SL-CoV strain (WIV1) and constructed an infectious clone of another strain (SHC014); significantly, these strains are closely related to SARS-CoV and capable of using the same cellular receptor (angiotensin-converting enzyme 2 [ACE2]) as SARS-CoV (6, 7). Despite the high similarity in genomic sequences and receptor usage of these two strains, there is still some difference between the N-terminal domains of the S proteins of SARS-CoV and other SL-CoVs, indicating that other unknown SL-CoVs are circulating in bats.Here we report the isolation of a new SL-CoV strain, named bat SL-CoV WIV16. SL-CoV WIV16 was isolated from a single fecal sample of Rhinolophus sinicus, which was collected in Kunming, Yunnan Province, in July 2013. The full genomic sequence of SLCoV WIV16 (GenBank accession number KT444582) was determined and contained 30,290 nucleotides (nt) and a poly(A) tail which is slightly larger than those of SARS-CoVs and other bat SL-CoVs (6, 8-13). The WIV16 genome has a 40.9% GϩC content and short untranslated regions (UTRs) of 264 and 339 nt at the 5= and 3= termini, respectively. Its gene organization is identical to that of WIV1 and slightly different from that of the civet SARS-CoV and other bat SL-CoVs due to an additional ORF (name ORFx) detected between the ORF6 and ORF7 genes of the WIV1 and WIV16 genomes (data not shown). The conserved transcriptional regulatory sequence was identified upstream of ORFx, indicating that this is likely to be a potential functional gene. The overall nucleotide sequence of WIV16 has 96% identity (higher than that of any p...

Chondrichthyan (cartilaginous fish) occupies a key phylogenetic position and is important for investigating evolutionary processes of vertebrates. However, limited whole genomes impede our in-depth knowledge of important issues such as chromosome evolution and immunity. Here, we report the chromosome-level genome of white-spotted bamboo shark. Combing it with other shark genomes, we reconstructed 16 ancestral chromosomes of bamboo shark and illustrate a dynamic chromosome rearrangement process. We found that genes on 13 fast-evolving chromosomes can be enriched in immune-related pathways. And two chromosomes contain important genes that can be used to develop single-chain antibodies, which were shown to have high affinity to human disease markers by using enzyme-linked immunosorbent assay. We also found three bone formation-related genes were lost due to chromosome rearrangements. Our study highlights the importance of chromosome rearrangements, providing resources for understanding of cartilaginous fish diversification and potential application of single-chain antibodies.

Bats have been identified as natural reservoirs of many viruses, including reoviruses. Recent studies have demonstrated the interspecies transmission of bat reoviruses to humans. In this study, we report the isolation and molecular characterization of six strains of mammalian orthoreovirus (MRV) from Hipposideros and Myotis spp. These isolates were grouped into MRV serotype 1, 2 or 3 based on the sequences of the S1 gene, which encodes the outer coat protein s1. Importantly, we found that three of six bat MRV strains shared high similarity with MRVs isolated from diseased minks, piglets or humans based on the S1 segment, suggesting that interspecies transmission has occurred between bats and humans or animals. Phylogenetic analyses based on the 10 segments showed that the genomic segments of these bat MRVs had different evolution lineages, suggesting that these bat MRVs may have arisen through reassortment of MRVs of different origins.