Molecular characterization of diapause hormone in Helicoverpa armigera

Diapause hormone (DH) is a neurohormone which is secreted from suboesophage al ganglion and responsible for induction of embryonic diapause in many ins ects. Using rapid amplification of the cDNA ends (RAGE) method, the cDNA en coding diapause hormone in Helicoverpa armigera, a main kind of crops pest was cloned. The nucleotide sequence reveals that the mRNA encodes an open r eading frame and the 25-aa DH peptide is localized at N-terminal region jus t after the signal peptide. A homology search showed that H. armigera DH ha s high homology with the diapause hormone of Bombyx mori and Helicoverpa te a; and it also belongs to the FXPRL neuropeptide family. Thus, H. armigera DH seems to be a new type of diapause hormone molecule.