Firing activities of neurosecretory cells producing diapause hormone and its related peptides in the female silkmoth, Bombyx mori. II. mandibular and maxillary cells.
A gene encoding a precursor polyprotein of diapause hormone (DH) and four related peptides is expressed by three groups of neurosecretory cells in the suboesophageal ganglion (SOG) of Bombyx mori. Long-term chronic recordings of firing activities were made from a common axonal tract (the maxillary nerve) of two groups of cells localized in the mandibular and maxillary neuromeres of SOG during pupal-adult development. Mandibular and maxillary cells usually produced a cluster of action potentials at an interval of 30-60 min during pupal-adult development and there was no significant difference in the firing activity profile between diapause-egg and non-diapause-egg producers. We suggest that rather than DH secretion, pupal mandibular and maxillary cells are involved in the secretion of DH-related neuropeptides. DH secretion seems to be assigned to the third group of cells (labial cells); hence, there may be different posttranslational processing of the precursor polyprotein in different neurosecretory cell groups.
Ichikawa
Toshio
T
Department of Biology, Faculty of Sciences, Kyushu University, Fukuoka, Japan. tichiscb@mbox.nc.kyushu-u.ac.jp
Kamimoto
Satoshi
S
D000200:Action Potentials; D000818:Animals; D012831:Bombyx / Q000235:genetics / Q000502:physiology*; D005260:Female; D005786:Gene Expression Regulation; D009479:Neuropeptides / Q000502:physiology*; D009490:Neurosecretory Systems / Q000502:physiology*; D017440:Photoperiod; D011498:Protein Precursors / Q000502:physiology*; D011679:Pupa; D013997:Time Factors
D009479:Neuropeptides; D011498:Protein Precursors; C075027:diapause hormone