Transcriptome-wide analysis of mRNA N6 -methyladenosine modification in the embryonic development of Spodoptera frugiperda.

Abstract

N6 -methyladenosine (m6 A) RNA is the most abundant modification of mRNA, and has been demonstrated in regulating various post-transcriptional processes. Many studies have shown that m6 A methylation plays key roles in sex determination, neuronal functions, and embryonic development in Drosophila and mammals. Here, we analyzed transcriptome-wide profile of m6 A modification in the embryonic development of the destructive agricultural pest Spodoptera frugiperda. We found that the 2 key mRNA m6 A methyltransferases SfrMETTL3 and SfrMETTL14 have high homologies with other insects and mammals, suggesting that SfrMETTL3 and SfrMETTL14 may have conserved function among different species. From methylated RNA immunoprecipitation sequencing analysis, we obtained 46869 m6 A peaks representing 8587 transcripts in the 2-h embryos after oviposition, and 41389 m6 A peaks representing 9230 transcripts in the 24-h embryos. In addition, 5995 m6 A peaks were differentially expressed including 3752 upregulated and 2243 downregulated peaks. Functional analysis with Gene Ontology and Kyoto Encyclopedia of Genes and Genomes suggested that differentially expressed m6 A peak-modified genes were enriched in cell and organ development between the 2- and 24-h embryos. By conjoint analysis of methylated RNA immunoprecipitation-seq and RNA-seq data, we found that RNA m6 A methylation may regulate the transcriptional levels of genes related to tissue and organ development from 2- to 24-h embryos. Our study reveals the role of RNA m6 A epigenetic regulation in the embryonic development of S. frugiperda, and provides new insights for the embryonic development of insects.