IMMUNOCYTOCHEMICAL LOCALIZATION OF A DIURETIC PEPTIDE MANDUCA DIURESIN (MASDPII) IN THE BRAIN AND SUBESOPHAGEAL GANGLION OF THE TOBACCO HAWKMOTH MANDUCA-SEXTA (LEPIDOPTERA, SPHINGIDAE)

A purified polyclonal antibody against synthetic Manduca diuresin (formerly named MasDPII) was used to localize immunoreactive cell clusters in the protocerebrum and the suboesophageal ganglion of adult, larval, and pupal stages of Manduca sexta. In adults and pharate adults, strong immunostaining was found in type IIb median neurosecretory cells and IIa(1-3) cells. Moderate staining was observed in the maxillary, mandibular, and labial cell clusters in the suboesophageal ganglion. In larvae, immunostaining was found in four IIa cells and in the maxillary, mandibular, and labial cell clusters of the suboesophageal ganglion. In the early pupal stage, six to eight type IIa cells were immunopositive and two clusters of developing type IIb cells showed positive staining. Furthermore, maxillary, mandibular, and labial cell clusters in the pupal suboesophageal ganglion also contained immunoreactive material. In all stages, nervi corporis cardiaci-1+2 and the retrocerebral complex showed immunoreactivity. While preadsorption of purified antibody with another diuretic peptide from M. sexta brain, MasDH, slightly reduced the immunostaining by the Manduca diuresin antibody, preadsorption with Manduca diuresin completely abolished immunoreactivity in all of the cells previously mentioned. The findings suggest the presence of Manduca diuresin or Manduca diuresin-like peptides in larval and pupal type IIa cells and in the suboesophageal ganglion of M. sexta in all three developmental stages. (C) 1994 Wiley-Liss, Inc