Publication Date:
1996-01-05
Description:
Developing insects repeatedly shed their cuticle by means of a stereotyped behavior called ecdysis, thought to be initiated by the brain peptide eclosion hormone. Here an ecdysis-triggering hormone, Mas-ETH, is described from the tobacco hornworm Manduca sexta. Mas-ETH contains 26 amino acids and is produced by a segmentally distributed endocrine system of epitracheal glands (EGs). The EGs undergo a marked reduction in volume, appearance, and immunohistochemical staining during ecdysis, at which time Mas-ETH is found in the hemolymph. Injection of EGs extract or synthetic Mas-ETH into pharate larvae, pupae, or adults initiates preecdysis within 2 to 10 minutes, followed by ecdysis. Sensitivity to injected Mas-ETH appears much earlier before ecdysis and occurs with shorter latency than that reported for eclosion hormone. The isolated central nervous system responds to Mas-ETH, but not to eclosion hormone, with patterned motor bursting corresponding to in vivo preecdysis and ecdysis. Mas-ETH may be an immediate blood-borne trigger for ecdysis through a direct action on the nervous system.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Zitnan, D -- Kingan, T G -- Hermesman, J L -- Adams, M E -- New York, N.Y. -- Science. 1996 Jan 5;271(5245):88-91.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Entomology, University of California, Riverside 92521, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/8539606" target="_blank"〉PubMed〈/a〉
Keywords:
Amino Acid Sequence
;
Animals
;
Central Nervous System/drug effects/physiology
;
Endocrine Glands/chemistry/cytology/physiology
;
Hemolymph/chemistry
;
Insect Hormones/chemistry/isolation & purification/pharmacology/*physiology
;
Larva/physiology
;
Manduca/*chemistry/physiology
;
Molecular Sequence Data
;
Molecular Weight
;
*Molting
;
Motor Neurons/drug effects/physiology
;
Peptides/chemistry/isolation & purification/pharmacology/*physiology
;
Pupa/physiology
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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