Enzyme linked immunosorbent assay for Manduca sexta allatostatin (Mas-AS), isolation and measurement of Mas-AS immunoreactive peptide in Lacanobia oleracea

Abstract

Using polyclonal antisera to Manduca sexta allatostatin (Mas-AS), an indirect ELISA has been developed which allows detection of Mas-AS-like immunoreactivity in single brain extracts of larval M. sexta and Lacanobia oleracea. Liquid chromatography of brain extracts from M. sexta and L. oleracea revealed two distinct immunoreactive areas, one co-eluting with synthetic Mas-AS and the other a more hydrophobic area. The Mas-AS co-eluting immunoreactive factor from L. oleracea was isolated and found to have a molecular mass in agreement with that of Mas-AS. In Periplaneta americana only the Mas-AS co-eluting fraction was observed. In L. oleracea Mas-AS-like immunoreactivity was also distributed throughout the central nervous system, in the haemolymph (plasma and haemocytes) and associated with midgut and Malpighian tubules. This widespread distribution suggests alternative roles for Mas-AS, other than the control of juvenile hormone biosynthesis. The relative amounts of Mas-AS immunoreactivity in brains of L. oleracea at selected developmental stages raises some questions as to the role of Mas-AS in the control of JH biosynthesis.