IDENTIFICATION OF NEUROENDOCRINE CELLS PRODUCING A DIURETIC HORMONE IN THE TOBACCO HORNWORM MOTH, MANDUCA-SEXTA

Separate antisera were raised to the N- and C-terminal half of the diuretic hormone from Manduca sexta. Antisera against the two halves of this peptide recognized the same cells in M. sexta, and preabsorption of the antisera with the peptides used as antigens abolished the immunoreactivity, confirming their specificity. The antisera reacted with two median neurosecretory cells on each side of the protocerebral groove in larvae, and with a group of about 80 small median neurosecretory cells in the adult, as well as their axons to, and their axon terminals in, the corpora cardiaca. During the early pupal stages, small cells, which are possibly derived from a common neuroblast, differentiate into immunoreactive neurosecretory cells, which explains the large increase in cell numbers in the adult. In the sleepy sulphur butterfly, Eurema nicippe, homologous median neurosecretory cells in the adult were immunoreactive with both antisera.