A Day in the Life: Identification of Developmentally Regulated MicroRNAs in the Colorado Potato Beetle (Leptinotarsa decemlineata; Coleoptera: Chrysomelidae)

Abstract

The Colorado potato beetle (Leptinotarsa decemlineata (Say)) is an important pest of the cultivated potato (Solanum tuberosum (L.) [Solanales: Solanaceae]). With its broad resistance toward commonly used insecticides, it is clear that more sophisticated control strategies are needed. Due to their importance in insect development, microRNAs (miRNAs) represent a potential tool to employ in insect control strategies. However, most studies conducted in this area have focused on model species with well-annotated genomes. In this study, next-generation sequencing was used to catalogue the miRNAs produced by L. decemlineata across all eight stages of its development, from eggs to adults. For most stages, the length of miRNAs peaked between 21 and 22 nt, though it was considerably longer for the egg stage (26 nt). Global profiling of miRNAs revealed three distinct developmental clusters: 1) egg stage; 2) early stage (first, second, and third instar); and 3) late stage (fourth instar, prepupae, pupae, and adult). We identified 86 conserved miRNAs and 33 bonafide novel miRNAs, including stage-specific miRNAs and those not previously identified in L. decemlineata. Most of the conserved miRNAs were found in multiple developmental stages, whereas the novel miRNAs were often stage specific with the bulk identified in the egg stage. The identified miRNAs have a myriad of putative functions, including growth, reproduction, and insecticide resistance. We discuss the putative roles of some of the most notable miRNAs in the regulation of L. decemlineata development, as well as the potential applications of this research in Colorado potato beetle management.

Unveiling gene expression regulation of the Bacillus thuringiensis Cry3Aa toxin receptor ADAM10 by the potato dietary miR171c in Colorado potato beetle

“…All putative CPB miRNAs targeting the CPB‐ADAM10 gene identified in CPB larvae feeding on potato cv. Vivaldi in the present work were also detected by Wiebe et al 38 . in all stages of development of CPB feeding on potato cv.…”

“…In CPB, the miRNA profile has been shown to change throughout development 38 and in adult beetles differentially expressed miRNAs were identified in response to environmental and chemical stresses such as low temperatures 39 and exposure to imidacloprid 40 . To explore the potential regulation of the CPB‐ADAM10 gene by miRNAs in CPB larvae feeding on potato cv.…”

Exposure to Temperature and Insecticides Modulates the Expression of Small Noncoding RNA-Associated Transcripts in the Colorado Potato Beetle, Leptinotarsa decemlineata (Coleoptera: Chrysomelidae)

“…Next-generation sequencing-based study revealed 14 upregulated and 19 downregulated miRNAs in this potato pest treated to imidacloprid ( Morin et al 2017b ). Assessment of miRNA expression in different stages of L. decemlineata development revealed multiple conserved and novel miRNAs as well as identified putative roles underlying insecticide resistance for select miRNAs ( Wiebe et al 2020 ). While multiple reports support modulation of miRNAs in insects exposed to insecticides, information is sparse regarding differential expression of piRNAs following similar treatments.…”

Leveraging RNA Interference to Impact Insecticide Resistance in the Colorado Potato Beetle, Leptinotarsa decemlineata

“…Interestingly, a recent study using whole-genome sequencing and transcriptomics information highlighted comparable genetic pathways, but different genes, used by L. decemlineata to develop insecticide resistance [ 58 ]. Finally, it is noteworthy to mention information stemming from different groups that revealed miRNAs, short non-coding transcripts that can regulate gene expression in a posttranscriptional manner, with potential roles for insecticide resistance and response in L. decemlineata [ 59 , 60 ]. Overall, it is clear from the molecular players presented in this section that many leads with a likely relevance for insecticide resistance in L. decemlineata have emerged over the past decade.…”