ABSTRACT
COVID-19 has not only created a pandemic but also affected both economically and socially in all countries. It has further created a socio-economic chaos throughout Latin America. Currently, some new SARS-CoV-2 variants are circulating in Latin America and one among the significant variant belongs to the P.1 lineage (B.1.1.28.1) that has 17 mutations. The essential modifications located in the spike glycoprotein RBD include E484K, K417T and N501Y. Along with the P.1 lineage, P.2 lineage (B.1.1.28.2) has also appeared recently. Details on all the variants are unknown, along with the Brazil variants at this time. Therefore, we call for intensive research to collect more data to understand the variants' virulence and the effects on vaccine efficacy.
ABSTRACT
RNA silencing is a remarkable type of gene regulation. This process has been found to occur in many different organisms such as plants (co-suppression), fungi (quelling), and animals (RNA interference; RNAi). Double-stranded RNA (dsRNA) is a potent trigger in RNA silencing mechanisms operating in a wide range of organisms. This mechanism recognizes dsRNA and processes them into small 21-25nt RNAs (smRNAs). Small RNAs can guide post-transcriptional degradation of complementary messenger RNAs and in plants, transcriptional gene silencing is occurred by methylation of homologous DNA sequences. In plants, it serves as an antiviral defense, and many plant viruses encode suppressors of silencing such as helper component-proteinase of potyviruses (HC-Pro) and the p25 protein encoded by potato virus X (PVX). HC-Pro acts by preventing accumulation of smRNAs that provide specificity determinant for homologous RNA degradation, but p25 viral protein acts by targeting the mobile silencing signal. The encouraging view is that RNA silencing is part of a sophisticated network of interconnected pathways for cellular defense and development and that it may become a powerful tool to manipulate gene expression experimentally.