Crumbs proteins stabilize the cone mosaics of photoreceptors and improve vision in zebrafish

Although the unique organization of vertebrate cone mosaics was first described long ago,both their underlying molecular basis and physiological significance are largely unknown.Here,we demonstrate that Crumbs proteins,the key regulators of epithelial apical polarity,establish the planar cellular polarity of photoreceptors in zebrafish.Via heterophilic Crb2a-Crb2b interactions,the apicobasal polarity protein Crb2b restricts the asymmetric planar distribution of Crb2a in photoreceptors.The planar polarized Crumbs proteins thus balance intercellular adhesions and tension between photoreceptors,thereby stabilizing the geometric organization of cone mosaics.Notably,loss of Crb2b in zebrafish induces a nearsightedness-like phenotype in zebrafish accompanied by an elongated eye axis and impairs zebrafish visual perception for predation.These data reveal a detailed mechanism for cone mosaic homeostasis via previously undiscovered apical-planar polarity coordination and propose a pathogenic mechanism for nearsightedness.     

Sustainability of SARS-CoV-2 Induced Humoral Immune Responses in COVID-19 Patients from Hospitalization to Convalescence Over Six Months

Virologica Sinica - Understanding the persistence of antibody in convalescent COVID-19 patients may help to answer the current major concerns such as the risk of reinfection, the protection period...     

Fur Seal Feces-Associated Circular DNA Virus Identified in Pigs in Anhui,China

Fur seal feces-associated circular DNA virus(FSfa CV) is an unclassified circular replication-associated protein(Rep)-encoding single-stranded(CRESS) DNA virus that has been detected in mammals(fur seals and pigs). The biology and epidemiology of the virus remain largely unknown. To investigate the virus diversity among pigs in Anhui Province,China, we pooled 600 nasal samples in 2017 and detected viruses using viral metagenomic methods. From the assembled contigs, 12 showed notably high nucleotide acid sequence similarities to the genome sequences of FSfa CVs. Based on these sequences, a full-length genome sequence of the virus was then obtained using overlapping PCR and sequencing, and the virus was designated as FSfa CV-CHN(Gen Bank No. MK462122). This virus shared 91.3% and 90.9% genome-wide nucleotide sequence similarities with the New Zealand fur seal strain FSfa CV-as50 and the Japanese pig strain FSfa CVJPN1, respectively. It also clustered with the two previously identified FSfa CVs in a unique branch in the phylogenetic tree based on the open reading frame 2(ORF2), Rep-coding gene, and the genome of the reference CRESS DNA viruses.Further epidemiological investigation using samples collected in 2018 showed that the overall positive rate for the virus was 56.4%(111/197) in Anhui Province. This is the first report of FSfa CVs identified in pigs in China, and further epidemiological studies are warranted to evaluate the influence of the virus on pigs.     

A Multicenter Study of Viral Aetiology of Community-Acquired Pneumonia in Hospitalized Children in Chinese Mainland

Virologica Sinica - Community-acquired pneumonia (CAP) is one of the leading causes of morbidity and mortality in children worldwide. In this study, we aimed to describe the aetiology of viral...     

PML Suppresses Influenza Virus Replication by Promoting FBXW7 Expression

Virologica Sinica - Influenza A viruses (IAV) are responsible for seasonal flu epidemics, which can lead to high morbidity and mortality each year. Like other viruses, influenza virus can hijack...