Identification and characterization of microRNAs in immature stage of the beneficial predatory bug Arma chinensis Fallou (Hemiptera: Pentatomidae)

Authors: YIN, YANFANG - USDA-ARS Sino-american Biological Control Laboratory; ZHU, YANJUAN - USDA-ARS Sino-american Biological Control Laboratory; MAO, JIANJUN - USDA-ARS Sino-american Biological Control Laboratory; Gundersen-Rindal, Dawn; LIU, CHENXI - USDA-ARS Sino-american Biological Control Laboratory

Submitted to: Archives of Insect Biochemistry and Physiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/16/2021
Publication Date: 6/1/2021
Citation: Yin, Y., Zhu, Y., Mao, J., Gundersen, D.E., Liu, C. 2021. Identification and characterization of microRNAs in immature stage of the beneficial predatory bug Arma chinensis Fallou (Hemiptera: Pentatomidae). Archives of Insect Biochemistry and Physiology. https://doi.org/10.1002/arch.21796.
DOI: https://doi.org/10.1002/arch.21796

Interpretive Summary: Arma chinensis is an insect species that preys upon a wide variety of insects and can effectively suppress numerous significant agricultural and forest pests. Understanding the molecular mechanisms underlying and regulating the development of beneficial insects like is important for their mass rearing to facilitate use in pest management. However, there have been no analyses of molecular processes regulating these predatory bugs. miRNAs are small molecules that play important roles regulating gene expression and can influence significant biological processes in insects, such as immunity, cell differentiation, growth and development. The current study evaluated miRNA profiles associated with early life stages of A. chinensis to better understand their related regulatory pathways and mechanisms. New miRNAs were discovered and the assessment of their predicted functions provided comprehensive understanding of their potential roles in regulation of biological processes of A. chinensis. This information will be useful to scientists and those involved in biological pest control.

Technical Abstract: Background: miRNAs are small non-coding RNAs that play important roles regulating gene expression at post-transcriptional level and can influence significant biological processes of insects, such as immunity, cell differentiation, growth and development, and apoptosis. Arma chinensis is a predaceous insect species that preys upon a wide variety of insect pest species, and can effectively suppress significant agricultural and forest pests within the orders Lepidoptera, Coleoptera, Hymenoptera, and Hemiptera. Understanding the molecular mechanisms underlying and regulating the development of beneficial insects is important for their mass rearing to facilitate use in pest management. However, there have been no analyses of processes regulating gene expression including post-transcriptional miRNA regulation in predatory bugs. The current study evaluates miRNA expression profiles associated with nymphal stages of A. chinensis and their potential genetic targets in order to better decipher their related regulatory pathways and mechanisms. Results: High throughput analyses identified a total of 1076 miRNAs from 107 raw reads, including 812 conserved miRNAs and 264 novel miRNAs with a small RNA length distribution peak of 22nt. Expression profiles showed a total of 225 miRNAs were differentially expressed among five A. chinensis nymphal instar libraries. 4303 potential gene targets for these 225 miRNAs were predicted by comprehensive analyses using miRanda, PITA and RNAhybrid. GO annotation of predicted A. chinensis target genes suggested key processes regulated by miRNAs involved biological regulation, cellular regulation, protein modification, RNA biosynthesis, and signal transduction. KEGG pathway analyses suggested A. chinensis genetic pathways regulated by miRNAs included longevity regulating, tryptophan metabolism, extracellular matrix (ECM)-receptor interaction, pentose phosphate, and sugar metabolism. Conclusion: This study represents the first comprehensive analysis of predatory bug A. chinensis-encoded miRNAs through high throughput sequencing and predicts genes and biological processes regulated by newly identified miRNAs through analyzing their differential expression in and across five nymphal instars. In addition to identifying new miRNAs and expanding miRBase data, assessment of their predicted functions provides new comprehensive understanding of potential miRNA roles in regulation of biological processes of A. chinensis, and forms a foundation for further investigating roles of specific miRNAs.