Expression profiling of a diapause-specific peptide (DSP) of the leaf beetle Gastrophysa atrocyanea and silencing of DSP by double-strand RNA.

A diapause-specific peptide (DSP) composed of 41 amino acid residues including 6 cysteines, has been isolated from diapausing adults of the leaf beetle Gastrophysa atrocyanea. In this study, DSP was found to be expressed primarily in diapausing adults and to a minor extent in pupae, but not in eggs, larvae, or post-diapausing adults. DSP was not induced by bacterial or fungal challenge. DSP-less adults were generated by the injection of double-stranded RNA (dsRNA) corresponding to the dsp gene into pre-diapausing adults. Gene silencing induced by dsRNA was found to be a useful tool for the analysis of DSP in diapausing adults. DSP-less adults showed similar burrowing behavior and oxygen consumption as control insects suggesting that DSP is not essential for the normal onset and maintenance of diapause.