Análise evolutiva de miRNAs e proteínas envolvidas em sua via de processamento em cnidários

Abstract

Cnidarian, phylum of the kingdom Animalia, has great ecological and economic importance, due to the characteristics of high capacity of adaptation to adverse environments. Mechanisms that intercede for changes in gene expression in response to stress remain unknown. A better understanding of the regulatory mechanisms of expression can make it possible to overcome some of the current environmental challenges. MiRNAs it has been considered important in the mRNA expression control. The miRNAs in plants and animals are well studied, however, there is an evolutionary gap on the emergence of these in these two kingdoms. The most accepted hypothesis is the convergent evolution, where the miRNAs are believed to have evolved independently, without a common ancestor. In order to better understand these organisms and to identify vegetal traces, the aim of this work was to search for proteins involved in the biogenesis of miRNAs, precursors of miRNAs and their mature ones in four cnidarians: Exaiptasia pallida, Acropora digitifera, Orbicella faveolata and Stylophora pistillata genomes, transcriptomes and proteomes. Proteins were identified with the BLASTp tool, where Arabidopsis thaliana and Caenorhabditis elegans sequences were used as a query against the cnidarian proteome. An optimized software with filters for conserved features was used to search for and identify putative precursors. Mature miRNAs were identified with the aid of miRBase. Proteins and plant miRNAs were identified in the cnidarians. This suggests a common ancestor between animals and plants. Thus, our preliminary results support our hypothesis on the divergent evolution of miRNAs in different kingdoms.