ISSN:
1432-136X
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Summary Head segments and brains were extirpated from embryos of the tobacco hornworm,Manduca sexta, extracted and the resulting extracts assayed for prothoracicotropic hormone (PTTH) activity on prothoracic glands from day 3 fifth instar larvae and day 0 pupae. Dose-response curves were generated and indicated the presence of PTTH activity in embryonic brains and head segments, suggesting a role(s) for this neurohormone during embryogenesis. Maximal PTTH activity was found in brains from embryos 117 h post-oviposition, just prior to hatching, but activity was also noted in head segments as early as 24 h postoviposition. These data on PTTH and those on ecdysteroids and juvenile hormones in embryos suggest that these 3 classes of hormones which control insect post-embryonic development, may also be involved in the regulation of developmental processes in the embryo.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00693354
Permalink