title: Development associated profiling of chitinase and microRNA of Helicoverpa armigera identified chitinase repressive microRNA.
abstract: Expression of chitinase is developmentally regulated in insects in consonance with their molting process. During the larval-larval metamorphosis in Helicoverpa armigera, chitinase gene expression varies from high to negligible. In the five-day metamorphic course of fifth-instar larvae, chitinase transcript is least abundant on third day and maximal on fifth day. MicroRNA library prepared from these highest and lowest chitinase-expressing larval stages resulted in isolation of several miRNAs. In silico analysis of sequenced miRNAs revealed three miRNAs having sequence similarity to 3'UTR of chitinase. Gene-targeted specific action of these miRNAs, was investigated by luciferase reporter having 3'UTR of chitinase. Only one of three miRNAs, miR-24, inhibited luciferase expression. Further, a day-wise in vivo quantification of miR-24 in fifth-instar larvae revealed a negative correlation with corresponding chitinase transcript abundance. The force-feeding of synthetic miR-24 induced significant morphological aberrations accompanied with arrest of molting. These miR-24 force-fed larvae revealed significantly reduced chitinase transcript abundance.
authors.affiliation: International Center for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, P.O. Box 10504, New Delhi-110067, India.
authors.forename: Neema
authors.initials: N
authors.lastname: Agrawal
authors.forename: Bindiya
authors.initials: B
authors.lastname: Sachdev
authors.forename: Janneth
authors.initials: J
authors.lastname: Rodrigues
authors.forename: K Sowjanya
authors.initials: KS
authors.lastname: Sree
authors.forename: Raj K
authors.initials: RK
authors.lastname: Bhatnagar
mesh_terms: D020413:3' Untranslated Regions; D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D002688:Chitinases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D007814:Larva / Q000235:genetics / Q000378:metabolism; D008675:Metamorphosis, Biological / Q000235:genetics; D035683:MicroRNAs / Q000235:genetics; D008969:Molecular Sequence Data; D009036:Moths / Q000201:enzymology / Q000235:genetics*; D010641:Phenotype; D015203:Reproducibility of Results; D013997:Time Factors; D014158:Transcription, Genetic
chemical_list: D020413:3' Untranslated Regions; D035683:MicroRNAs; D002688:Chitinases