title: Identification of microRNAs in Helicoverpa armigera and Spodoptera litura based on deep sequencing and homology analysis.
abstract: The current identification of microRNAs (miRNAs) in insects is largely dependent on genome sequences. However, the lack of available genome sequences inhibits the identification of miRNAs in various insect species. In this study, we used a miRNA database of the silkworm Bombyx mori as a reference to identify miRNAs in Helicoverpa armigera and Spodoptera litura using deep sequencing and homology analysis. Because all three species belong to the Lepidoptera, the experiment produced reliable results. Our study identified 97 and 91 conserved miRNAs in H. armigera and S. litura, respectively. Using the genome of B. mori and BAC sequences of H. armigera as references, 1 novel miRNA and 8 novel miRNA candidates were identified in H. armigera, and 4 novel miRNA candidates were identified in S. litura. An evolutionary analysis revealed that most of the identified miRNAs were insect-specific, and more than 20 miRNAs were Lepidoptera-specific. The investigation of the expression patterns of miR-2a, miR-34, miR-2796-3p and miR-11 revealed their potential roles in insect development. miRNA target prediction revealed that conserved miRNA target sites exist in various genes in the 3 species. Conserved miRNA target sites for the Hsp90 gene among the 3 species were validated in the mammalian 293T cell line using a dual-luciferase reporter assay. Our study provides a new approach with which to identify miRNAs in insects lacking genome information and contributes to the functional analysis of insect miRNAs.
authors.affiliation: Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, P.R. China.
authors.forename: Xie
authors.initials: X
authors.lastname: Ge
authors.forename: Yong
authors.initials: Y
authors.lastname: Zhang
authors.forename: Jianhao
authors.initials: J
authors.lastname: Jiang
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhong
authors.forename: Xiaonan
authors.initials: X
authors.lastname: Yang
authors.forename: Zhiqian
authors.initials: Z
authors.lastname: Li
authors.forename: Yongping
authors.initials: Y
authors.lastname: Huang
authors.forename: Anjiang
authors.initials: A
authors.lastname: Tan
mesh_terms: D000818:Animals; D012831:Bombyx / Q000235:genetics; D059014:High-Throughput Nucleotide Sequencing / Q000379:methods*; D007313:Insecta / Q000235:genetics*; D035683:MicroRNAs / Q000235:genetics*; D018411:Spodoptera / Q000235:genetics*
chemical_list: D035683:MicroRNAs
keywords: Bombyx mori.; Helicoverpa armigera; Spodoptera litura; deep sequencing; homolog analysis; microRNA