Identification of microRNAs and their target transcripts in the migratory locust adult brain revealed their roles in the epigenetic regulation of polyphenisms

Abstract

To investigate the unknown epigenetic regulation mechanisms underlying polyphenisms by microRNAs (miRNAs) in migratory locusts, we performed small RNA-sequencing (RNA-seq) analysis using 12 different groups according to habitat, sex, and phase. We identified a total of 175 miRNA clusters from 12 small RNA-seq data sets using a bioinformatics tool designed for this study. We found differences among expressed mature miRNAs among groups. The numbers of miRNAs detected from each group ranged from 35 to 115. In addition, 8–35 habitat-, sex- and phase-specific miRNAs were identified. To investigate the in vivo functions of the miRNAs in polyphenisms, target mRNAs for sex- and phase-specific miRNAs were predicted. Gene Ontology analysis results for target mRNAs suggested that sex- and phase-specific miRNAs in the locust brains may be involved with the polyphenisms by regulating the expressions of target mRNAs in various physiological functions. Thus, further studies using the sex- and phase-specific miRNAs identified in this study may allow the development of migratory locust-specific control tools (e.g., male and female sterilization techniques) or management methods to prevent locust transition from solitary to gregarious phases.