1997年11月
Neuroendocrine control of diapause hormone secretion in the silkworm, Bombyx mori
Journal of Insect Physiology
- ,
- ,
- 巻
- 43
- 号
- 12
- 開始ページ
- 1101
- 終了ページ
- 1109
- 記述言語
- 英語
- 掲載種別
- DOI
- 10.1016/S0022-1910(97)00083-8
To clarify the control mechanism of diapause hormone (DH) secretion in the silkworm Bombyx marl a series of anatomical and pharmacological experiments were carried out. The arrangement of 'diapause' and 'non- diapause' eggs in the ovarioles of the moths was determined by the coloration method to estimate the accumulation of 3-hydroxykynurenine in the eggs. The females destined to lay non-diapause eggs (non-diapause producers) had diapause eggs in their ovaries if their subesophageal ganglions (Sg) had been surgically removed at 2 days after larval-pupal ecdysis or later. In contrast when the surgical extirpation extended to the brain and the corpora cardiaca (CC)-corpora allata (CA) complex in addition to the Sg, the nondiapause producers had no diapause eggs. When the Sg was removed from the females destined to lay diapause eggs (diapause-producers), diapause eggs appeared in response to the treatment at 2 days after larval-pupal ecdysis, but the appearance of diapause eggs was delayed by 2 days when the brain-CC-CA complex was included among the organs removed. These observations suggested that DH is produced in Sg and transferred to the CC-CA complex, and that the secretion of DH from the complex is suppressed in non-diapause producers. The pattern of diapause and non-diapause eggs induced by the transection of the subesophageal connective in diapause and non-diapause producers suggested a regenerative and secretory capacity of the neurosecretory cells after the operation. The appearance of diapause eggs in non-diapause producers with transected protocerebrum of the brain confirmed that there was an inhibitory center in the protocerebrum. Changes in parts of the ovarioles containing diapause and non-diapause eggs with time of injection of γ-aminobutyric acid (GABA) and picrotoxin suggested that a GABAergic inhibitory mechanism in DH secretion may be active in non-diapause producers but inactive in diapause producers throughout the pupal stage.
- ID情報
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- DOI : 10.1016/S0022-1910(97)00083-8
- ISSN : 0022-1910
- SCOPUS ID : 0031278886