Identification and characterization of a POU transcription factor in the cotton bollworm, Helicoverpa armigera

Background: The POU family genes containing the POU domain are common in vertebrates and invertebrates and play critical roles in cell-type-specific gene expression and cell fate determination. Results: Har-POU, a new member of the POU gene family, was cloned from the suboesophageal ganglion of Helicoverpa armigera (Har), and its potential functions in the development of the central nervous system (CNS) were analyzed. Southern blot analysis suggests that a single copy of this gene is present in the H. armigera haploid genome. Har-POU mRNA is distributed widely in various tissues and expressed highly in the CNS, salivary gland, and trachea. In vitro-translated Har-POU specifically bound canonical octamer motifs on the promoter of diapause hormone and pheromone biosynthesis activating neuropeptide (DH-PBAN) gene in H. armigera. Expression of the Har-POU gene is markedly higher in the CNS of nondiapause-destined pupae than in diapause-destined pupae. Expression of the Har-POU gene in diapausing pupae was upregulated quickly by injection of ecdysone. Conclusion: Har-POU may respond to ecdysone and bind to the promoter of DH-PBAN gene to regulate pupal development in H. armigera.