Identification of microRNA and their potential role in regulation diapause termination in seven spot ladybird beetle, <i>Coccinella septempunctata</i>

Abstract Diapause is an alternative development stage in seven spot ladybird beetle, Coccinella septempunctata . However, the regulatory mechanism governing the initiation, maintenance, and termination of diapause in the seven-spot ladybird have not been extensively studied. MicroRNAs (miRNAs), a type of non-coding RNA, might be involved in diapause regulation and related physiological processes. The objective of this study is to investigate the potential involvement of miRNAs in diapause termination in C. septempunctata . High-throughput sequencing was used to identify miRNAs associated with diapause termination in C. septempunctata . A total of 769 miRNAs were identified, potentially implicated in diapause termination, including 673 evolutionarily conserved miRNA and 96 putatively novel-miRNAs. Among these, two evolutionarily conserved miRNAs, aae-miR-305-5P and tca-miR-277-5P, exhibited differential abundance during diapause termination compared to diapause. aae-miR-305-5P was overexpressed in diapause termination ladybird beetle and may be responsible for silencing the expression of candidate genes in peroxisome pathway associated with diapause termination. Conversely, tca-miR-277-5P was under-expressed in diapause termination and may promote the expression of genes related to the longevity regulating pathway, thereby increase the lifetime, a characteristic feature of diapause termination. In addition, a putatively novel-miRNA (unconservative_c62764) was overexpressed in diapause termination ladybird beetle, potentially contributing to the decreased expression of genes related to Wnt signaling pathway during diapause termination. These findings highlighting the significant roles of microRNAs in pathway such as longevity regulation, perisome function, and Wnt signaling, which may regulate diapause termination in C. septempunctata . This study might help us to unveil the miRNA involvement in gene expression regulation of diapause termination in insects.