Abstract
Developmental changes in the expression of a FMRFamide-like (Phe-Met-Arg-Phe-NH2) peptide or peptides in motoneurons of the tobacco hornworm, Manduca sexta, were demonstrated using immunohistochemical techniques. The onset of FMRFamide-like immunoreactivity (FLI) was gradual during larval growth but by the final larval stage, immunoreactivity was present in the majority of motoneurons. FLI then declined during metamorphosis and was absent in all identified adult motoneurons. We used a novel in vivo culture system to demonstrate that the steroid hormone, 20-hydroxyecdysone, regulates the loss of FLI in motoneurons during metamorphosis. The small commitment peak of ecdysteroid appears to shut off the program of neuropeptide accumulation that is characteristic of the larval state of the motoneurons. The prepupal peak of steroid then causes the rapid loss of stored FLI. This steroid-induced change in the neuropeptide content of motoneurons may reflect major changes in neuromuscular functions between the larval and adult stages.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.