Mode of Action of Pheromone Biosynthesis Activating Neuropeptide in Bombyx mori

Abstract

The production of sex pheromone in a number of moth species is controlled by pheromone biosynthesis activating neuropeptide (PBAN), which is secreted by the subesophageal ganglion (Raina and Klun 1984; Ohguchi et al. 1985; Ando et al. 1988; Raina 1988; Rafaeli and Soroker 1989a). Recently, a growing number of investigations have focused on the identification of the target organ of PBAN for a clearer understanding of the mode of action of this hormone. In Helicoverpa (Heliothis) armigera, Bombyx mori,and Spodoptera litura, the target organ of PBAN has been demonstrated to be the pheromone gland itself (Rafaeli and Soroker 1989b; Soroker and Rafaeli 1989; Arima et al. 1991; Fonagy et al. 1992a). According to another model, in H. zea, H. virescens, and H. subflexa, Helicoverpa-Heliothis PBAN does not act on pheromone glands but on the terminal abdominal ganglion (TAG) and the abdominal nerve cord transports PBAN to the TAG, which sends a different message to the gland (Teal et al. 1989a). Moreover, direct, neural stimulation induced by PBAN is suggested via axonal branches innervating the pheromone glands in H. zea and H. virescens (Christensen et al. 1991b). In addition, reports say that the corpus bursa is the target organ of PBAN in Argyrotaenia velutinana and that it produces the “bursa factor” responsible for pheromone production (Jurenka et al. 1991a). These findings suggest diverse physiological mechanisms of PBAN action depending on the lepidopteran species.