RESUMO
Previous work indicated that the nucleocapsid 203 mutation increase the virulence and transmission of the SARS-CoV-2 Alpha variant. However, Delta later outcompeted Alpha and other lineages, promoting a new wave of infections. Delta also possesses a nucleocapsid 203 mutation, R203M. Large-scale epidemiological analyses suggest a synergistic effect of the 203 mutation and the spike L452R mutation, associated with Delta expansion. Viral competition experiments demonstrate the synergistic effect in fitness and infectivity. More importantly, we found that the combination of R203M and L452R brings in a 3.2-fold decrease in neutralizing titers to the neutralizing serum relative to L452R-only virus. R203M/L452R show an increased fitness after the initiation of global vaccination programmes, possibly associated with the enhanced immune evasion. Another rapidly emerging variant Omicron also bears the 203 mutation. Thus, we proposed that nucleocapsid mutations play an essential role for the rise and predominance of variants in concern.
RESUMO
Omics technologies have profoundly promoted development and applications of metabolic engineering by analysis of cell metabolism at a system level. Whole genome transcription profiles have provided researchers more rigorous evaluation of cell phenotype and an increased understanding of cellular metabolism. Furthermore, transcriptome analysis can conduce to identification of effective gene targets for strain improvement, and consequently accelerates rational design and construction of microbial cell factories for desired product. In this review, we briefly introduced the principle of three main platforms of transcriptome, and reviewed the recent applications of the transcriptome to metabolic engineering, finally provided conclusions and future prospects.
