• Korean journal of applied entomology
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• v.61 no.1
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• pp.29-34
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• 2022

Pheromone biosynthesis in the pheromone gland is triggered from release of pheromone biosynthesis-activating neuropeptide (PBAN) synthesized in the suboesophageal ganglion. PBAN binds to its receptor on the epithelial cell membrane and activates signal transduction pathways for the pheromone biosynthesis. This study reviews sex pheromone, PBAN and its receptor, and pheromone biosynthesis pathway of Maruca vitrata.

• Korean journal of applied entomology
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• v.61 no.1
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• pp.15-28
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• 2022

Neuropeptides produced in neurosecretory cells are the largest group of insect hormones. They regulate various physiological functions, such as fat body homeostasis, feeding, digestion, excretion, circulation, reproduction, metamorphosis, and behavior throughout all life stages. The PRXamide peptide family (X, a variable amino acid) is a well-characterized neuropeptide component with a common amino acid sequence, PRXamide (NH₂), at the C-terminal end conserved across Insecta. The PRXamide peptides are classified into three subfamilies, each having diverse biological roles in insects: (1) pyrokinin (PK) includes the pheromone biosynthesis activating neuropeptide (PBAN) and the diapause hormone (DH), (2) the capability (CAPA) peptides, and (3) the ecdysis-triggering hormone (ETH). PBAN as a member of PK subfamily was first identified to stimulate pheromone biosynthesis in moths three decades ago. Since then, PBAN peptides have been extensively studied by various research groups from a broad spectrum of arthropods. In this paper, we briefly review insect PBAN molecules with emphasis on gene structure and expression, signal transduction, physiological mechanism in sex pheromone biosynthesis, and application for pest management.

• Proceedings of the Korean Society of Applied Entomolohy Conference
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• 2005.05a
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• pp.145-145
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• 2005

• Proceedings of the Korean Society of Sericultural Science Conference
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• 1997.06a
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• pp.51-72
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• 1997

Diapause hormone (DH) is a neuropeptide hormone which is secreted from the suboesophageal ganglion (SG) and is responsible for induction of embryonic diapause of the silkworm, Bombyx mori. DH is isolated from SGs and determined to be a 24 amino acid peptide amide. The cDNA encodes the polyprotein precursor from which DH, pheromone biosynthesis activating neuropeptide (PBAN) and three other neuropeptides are released and become matured. The C-terminal FXPRL-NH2 sequence of DH is essential but not sufficient for expression of full activity. Recently, we have isolated a unique hydrohobic peptide (VAP peptide) with a slight diapause egg induceing activity from organic solvent extracts of the male adult heads of the silkworm. The VAP peptide itself has no diapause inducing activity, but enhances DH activity through reducing ED50 value and the threshold concentration of DH. The DH-PBAN gene is composed of 6 exons interrupted by 5 introns and is expressed in 12 neurosecretory cells of the SG. The incubation of eggs at 25$^{\circ}C$, which induces embryonic diapause in the progeny, caused DH-PBAN mRNA content to increase at 5 different stages in the life cycle. By contrast, a 15$^{\circ}C$ incubation only induced expression of the gene at the late phrase adult stage. The temperature-controlled expression of DH-PBAN gene is closely correlated to the incidence of diapause, indicating that DH-PBAN gene expression is the initial event leading to diapause induction. DH acts to stimulate trehalase activity in developing ovary to bring about hyprglycogenism in mature eggs, a prerequisite metabolism for diapause initiation. Using in vivo and in vitro systems, DH is clearly shown to induce trehalase gene expression in developing ovaries. New protein synthesis is not needed for this process, but a Ca2+-dependent proteinkinase seems to be involved. Quite recently, we have sucessfully applied a new and potent trehalase inhibitor (Trehazoline) to reudce glycogen content in developing ovaries. The eggs deficient in glycogen were also able to enter diapause as the natural eggs do, so that we could provide the new egg system to reconsider the diapause associated metabolism other than the glycogen-sorbitol metabolic system.