title: An insect trypsin-like serine protease as a target of microRNA: utilization of microRNA mimics and inhibitors by oral feeding.
abstract: MicroRNAs (miRNAs) are non-coding small RNAs (18-25 nt) that play crucial roles in various biological processes, including development, as gene regulators. In this study, we identified a miRNA, har-miR-2002b, that is specifically expressed during larval stages of Helicoverpa armigera (cotton bollworm). For the first time, we explored the possibility of utilizing synthetic inhibitor and mimic of a miRNA by oral feeding and confirmed that the inhibitor and mimic can successfully inhibit/oversupply har-miR-2002b in H. armigera larvae. Bioassays by oral feeding indicated 70% reduction in fecundity and 40% larval mortality in the presence of har-miR-2002b mimic. In addition, a large proportion of those larvae that made it to the pupal stage were deformed and only few moths emerged from them. This implied an important role of har-miR-2002b in larval development and adult fecundity. A trypsin-like serine protease (Ha-TLP) was identified as a target of har-miR-2002b. In vivo and in vitro studies revealed that in the presence of the miRNA mimic Ha-TLP transcript/protein levels and enzyme activity were significantly reduced. In contrast, inhibition of har-miR-2002b led to significant up-regulation of Ha-TLP transcript levels. This is the first study which shows the potential of utilization of miRNA mimics and inhibitors in pest control by targeting specific insect genes.
authors.affiliation: School of Biological Sciences, The University of Queensland, Brisbane, St Lucia, QLD 4072, Australia.
authors.forename: Balachandran
authors.initials: B
authors.lastname: Jayachandran
authors.forename: Mazhar
authors.initials: M
authors.lastname: Hussain
authors.forename: Sassan
authors.initials: S
authors.lastname: Asgari
mesh_terms: D000818:Animals; D001483:Base Sequence; D005247:Feeding Behavior; D005260:Female; D019476:Insect Proteins / Q000235:genetics* / Q000378:metabolism; D007814:Larva / Q000201:enzymology / Q000235:genetics / Q000502:physiology; D008297:Male; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D009036:Moths / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development / Q000502:physiology; D010572:Pest Control, Biological / Q000379:methods*; D034622:RNA Interference; D012697:Serine Endopeptidases / Q000235:genetics* / Q000378:metabolism
chemical_list: D019476:Insect Proteins; D035683:MicroRNAs; C114880:trypsin-like serine protease; D012697:Serine Endopeptidases