title: Differential expression of microRNA species in a freeze tolerant insect, Eurosta solidaginis.
abstract: Freeze tolerance in insects is associated with a variety of adaptations including production of cryoprotectants, specialized proteins that regulate ice formation, and energy-saving mechanisms that strongly suppress the rates of metabolic processes in the oxygen-limited frozen state. We hypothesized that microRNAs (miRNAs), small non-coding transcripts that bind to mRNA, could play a role in the global regulation of energy-expensive mRNA translation in frozen insects and would be modulated at subzero temperatures. Expression levels of miRNA species were evaluated in control (5 °C) and frozen (-15 °C) goldenrod gall fly larvae, Eurosta solidaginis, using a miRNA microarray. Levels of miR-11, miR-276, miR-71, miR-3742, miR-277-3p, miR-2543b and miR-34 were significantly reduced in frozen larvae whereas miR-284, miR-3791-5p and miR-92c-3p rose significantly in frozen larvae. Target prediction for two miRNAs, miR-277-3p and miR-284, revealed potential regulation of transcripts involved in translation and the Krebs cycle. These data constitute the first report that differential expression of miRNAs occurs in a freeze tolerant insect and suggest a mechanism for reversible gene regulation during prolonged periods of freezing over the winter months, a mechanism that can be rapidly reversed to allow renewed translation of mRNA when temperatures rise and insects thaw.
authors: Department of Chemistry and Biochemistry, Université de Moncton, 18 Antonine-Maillet Avenue, Moncton, New Brunswick, Canada E1A 3E9.
authors: Lynn A
authors: LA
authors: Courteau
authors: Kenneth B
authors: KB
authors: Storey
authors: Pier
authors: P
authors: Morin
mesh_terms: D000064:Acclimatization; D000818:Animals; D005615:Freezing; D005786:Gene Expression Regulation; D035683:MicroRNAs / Q000235:genetics*; D033621:Tephritidae / Q000235:genetics* / Q000502:physiology
chemical_list: D035683:MicroRNAs