miRNA-seq in different development stages of Atrijuglans hetaohei. Atrijuglans hetaohei isolate:Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Hexapoda; Insecta; Pterygota; Neoptera; Endopterygota; Lepidoptera; Glossata; Ditrysia; Gelechioidea; Stathmopodidae; Atrijuglans

The miRNAs in two development stages of A. hetaohei were identified by high throughput sequencing with reference to the genome and miRNA databases of the silkworm. A total of 132 conserved miRNAs belonging to 64 families and seven novel miRNAs were obtained, among which 118 miRNAs have been identified in two libraries, four and 17 miRNAs were only detected to adult-specific and larval-specific libraries, respectively. The most abundant miRNAs in A. hetaohei were miR-1a-3p, let-7, miR-2766 and miR-184. Comparative analysis revealed that four novel miRNAs and 47 conserved miRNAs were differentially expressed (P < 0.05) between two libraries. Abundance changes of miRNAs were observed from larva to adult: 19 miRNAs were up-regulated and 21 miRNAs were down-regulated. The metamorphosis and apoptosis associated miRNAs including miR-1a-3p, miR-133, let-7, miR-2766, miR-184 and miR-34 were discussed for their predicted functions in insect development. The different expressions of these miRNAs were relevant to dorso-ventral axis formation, phototransduction, insect hormone biosynthesis, circadian rhythm and mitogen-activated protein kinase (MAPK) signaling pathway. QRT-PCR analysis of ten miRNAs showed similar expression patterns as high throughput analysis, most miRNAs were highly expressed in adult stage, while miR-8-3p, miR-305-3p and miR-2766 were highly expressed in larvae. The results preliminarily revealed the characterization of conserved and novel miRNAs in different development stages of A. hetaohei. The different expressions and associated functions of these miRNAs will provide a basis for understanding post-transcriptional level during insect development and growth.