Genome-wide CRISPR screening reveals key genes and pathways associated with 20-hydroxyecdysone signal transduction in the silkworm(Bombyx mori)

Metamorphosis is a complex developmental process involving multiple pathways and a large number of genes that are regulated by juvenile hormone(JH)and 20-hydroxyecdysone(20E).Despite important progress in understanding various aspects of silkworm biology,the hormone signaling pathway in the silkworm remains poorly understood.Genome-wide screening using clustered regularly interspaced short palindromic repeats(CRISPR)/CRISPR-associated protein 9(Cas9)-based libraries has recently emerged as a novel method for analyzing genome function,enabling further research into essential genes,drug targets,and virus-host interaction.Previously,we constructed a genome-wide CRISPR/Cas9-based library of the silkworm(Bombyx mori)and successfully revealed the genes involved in biotic or abiotic stress factor responses.In this study,we used our silkworm CRISPR library and large-scale genome-wide screening to analyze the key genes in the silkworm 20E signaling pathway and their mechanisms of action.Functional annotation showed that 20E regulates key proteins in processes that mainly occur in the cytoplasm and nucleus.Pathway enrichment analysis showed that 20E can activate phosphorylation and may affect innate immunity,interfere with intracellular nutrition and energy metabolism,and eventually cause cell apoptosis.The screening results were experimentally validated by generating cells with knockout alleles of the relevant genes,which had increased tolerance to 20E.Our findings provide a panoramic overview of signaling in response to 20E in the silkworm,underscoring the utility of genome-wide CRISPR mutant libraries in deciphering hormone signaling pathways and the mechanisms that regulate metamorphosis in insects.

Effectiveness of Inactivated COVID-19 Vaccines Against Symptomatic,Pneumonia,and Severe Disease Caused by the Delta Variant:Real World Study and Evidence—China,2021

Summary What is already known about this topic?Effectiveness of China’s 2 inactivated vaccines(BBIBPCorV and CoronaVac)against pre-Delta severe acute respiratory syndrome coronavirus-2(SARS-CoV-2)variants ranged from 47%to over 90%,depending on the clinical endpoint,and with greater effectiveness against more severe coronavirus disease 2019(COVID-19).During an outbreak in Guangdong,inactivated vaccine effectiveness(VE)against the Delta variant was 70%for symptomatic infection and 100%for severe COVID-19.However,separate or combined VE estimates for the two inactivated vaccines against Delta are not available.What is added by this report?In an outbreak that started in a hospital,VEs of completed primary vaccination with inactivated COVID-19 vaccines against symptomatic COVID-19,COVID-19 pneumonia,and severe COVID-19 caused by the Delta variant were 51%,61%,and 82%.Completed primary vaccination reduced the risk of progressing from mild to moderate or severe COVID-19 by 74%.VE estimates for BBIBP-CorV and CoronaVac or combined vaccination were similar,and partial vaccination was ineffective.What are the implications for public health practice?Completed primary vaccination with either of the 2 inactivated COVID-19 vaccines reduces risk of symptomatic COVID-19,COVID-19 pneumonia,and severe COVID-19 caused by the Delta variant.Completion of the completed primary vaccination with two doses is necessary for protection from Delta.