Approaches to Generating Monoclonal Antibodies to the Prothoracicotropic Hormone in Manduca Sexta

Abstract

The prothoracicotropic hormone (PTTH), the primary regulator of insect molting and metamorphosis, is a cerebral peptide which in at least two insects exists in multiple molecular forms. In the tobacco hornworm, Manduca sexta, two PTTHs (big ~28 kD and small ~7 kD) have been identified that activate larval and pupal prothoracic glands differentially (Bollenbacher et al., 1984). Similarly, in the silkworm, Bombyx mori, two comparable molecular weight classes of PTTH have been identified, with the small 4kD moiety apparently existing in three forms (Ishizaki et al., 1983; Nagasawa et al., 1984). The physiological significance of multiple forms is not known. In large part, the dearth of knowledge on PTTH has been a result of the difficulty encountered purifying the neurohormone.