Reproduction-associated immunoreactive peptides in the nervous systems of prosobranch gastropods

Antibodies against reproductive peptides of Aplysia and Lymnaea were used t o localize homologous immunoreactive peptides in the nervous systems of thr ee prosobranch species: Busycon canaliculatum, Concholepas concholepas, and Tegula atra. Positive control experiments in L. stagnalis demonstrated the broad species range of the anti-egg-laying hormone (anti-ELH) antibody use d in this study, and showed binding of anti-alpha-caudodorsal-cell peptide (anti-alpha-CDCP) to the same cells in cerebral and buccal ganglia. Dot imm unoassays with synthetic ELH confirmed the reactivity and sensitivity (<0.1 mu g) of the anti-ELH antibody. Experiments with preadsorbed antibody or n o primary antibody confirmed its specificity. In B. canaliculatum, clusters of more than 300 neuronal cell bodies immunor eactive to both anti-ELH and anti-alpha-CDCP were observed along the medial margins of left and right cerebral ganglia. Anti-alpha-CDCP reacted with a dditional small populations of cerebral ganglion neurons not stained by ant i-ELH. Anti-ELH and anti-alpha-CDCP also reacted with overlapping but diffe rent small populations of neurons in buccal ganglia. In C. concholepas and T. atra, ELH-like immunoreactivity was found in cerebral ganglia, and in T. atra in fibers in the cerebral ganglia and cerebral-pedal connectives. Thu s, cerebral ganglia are the major locus of the ELH-like immunoreactivity in prosobranchs.