WILLIAMS, Judith; MELTON, Scott; Univ. of Southern Miss Gulf Coast; same: Immunohistochemical Evidence of Insect Pheromonotropic Melanization Peptide in Copepods

Copepods and insects are both members of the Phylum Arthropoda and are separated from one another based on morphology of mouthparts, antenna, wings and segmentation. While very different, they share striking similarities in many physiological functions and ecological adaptations. Often copepods are referred to as the “insects of the sea”. Copepods and insects both are highly pigmented, use pheromones in mate-seeking behavior and many undergo programmed dormancy (diapause) during which time they utilize lipids stored prior to dormancy. A great deal of information exists on the neurophysiology/endrocrinology of insects, but little exists on the physiology of copepods. Using dotblots and immunohistochemistry, we tested a monoclonal antibody against &alpha-pheromonotropic melanization peptide (PMP) from a Lepidopteran insect on whole copepod extracts. Α-PMP is quite similar in molecular structure and activity to pheromone biosynthesis activating neuropeptide (PBAN), a well known pheromonotropic neuropeptide prevelant throughout the insect phyla. In the silkworm Bombyx mori, production of Diapause Hormone (DH), PBAN and three other FXPRLamide peptides are controlled by one gene. Dotblots performed on whole extracts of copepods (Orders Calanoida & Harpacticoida) reveal positive results for α-PMP antibody. To test the presence of the antibody in neural ganglia of copepods, the large calanoids Aglaodiaptomus stagnalis were embedded in wax, serially sectioned and stained with a neurofilament antibody to localize neural tissue. Sequential slides were stained with the α-PMP antibody using an avidin-biotinylated peroxidase kit. Copepod neual tissue showed positive reaction to the α-PMP antibody. This is the first evidence of insect neuropeptide antibodies cross-reacting in copepods.