Sex Pheromone Production in the Silkworm, Bombyx mori, Is Mediated by Store-Operated Ca²⁺ Channels

Abstract

In most female moths, pheromone biosynthesis activating neuropeptide (PBAN) regulates sex pheromone production by stimulating an influx of extracellular Ca²⁺. Little is known about the plasma membrane channel or how the PBAN stimulus is communicated to the channel. Fluorescent Ca²⁺ imaging techniques confirmed PBAN-induced Ca²⁺ influx in the silkworm, Bombyx mori, and showed that the PBAN response is reduced with repeated stimulation. Compounds known to impact Ca²⁺ signaling were examined for their effects on sex pheromone production. These experiments demonstrated that the PBAN signal is likely mediated by a store-operated channel (SOC). SOC blockers, SKF-96365 and 2-aminoethoxydiphenyl borate, abolished sex pheromone production, as did flufenamic acid, a blocker of transient receptor potential (TRP) channels. Thapsigargin mimicked the pheromonotropic effects of PBAN. Similar results were seen when PBAN-induced lipase activity was assayed. Conversely, 1-oleoyl-2-acetyl-sn-glycerol and arachidonic acid, activators of diacylglycerol-dependent Ca²⁺ channels, had no effect on bombykol production.

• store-operated channel
• pheromone biosynthesis activating neuropeptide (PBAN)
• Bombyx mori
• calcium influx
• sex pheromone biosynthesis