Death commitment in the anterior silk gland of the silkworm, Bombyx mori
Death commitment in the anterior silk gland of the silkworm, Bombyx mori
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DOI：
10.1016/j.jinsphys.2004.10.012
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发表时间：
2005-01-01
影响因子：
2.2
通讯作者：
Sakurai, S
中科院分区：
文献类型：
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作者：
Kakei, M;Iwami, M;Sakurai, S
昆虫甾体激素20-羟基蜕皮激素（20 E）可引起家蚕前丝腺细胞程序性死亡（PCD）。我们试图通过检测ASG对20 E和保幼激素类似物（JHA）的体内和体外反应来确定死亡承诺（死亡承诺）的时间。5龄第6天后期获得的ASG经20 E处理后完成PCD，而第4天获得的ASG经20 E处理后未发生PCD。助理秘书长在第5天中午开始有能力对20 E作出反应。对20 E有反应的ASG对JHA不敏感，表明ASG在能够对20 E作出反应之前就已经死亡。局部应用JHA在第4天抑制20 E诱导的PCD，但在第5天没有这样做，表明死亡承诺可能发生在第4和第5天之间。我们还确定了时间的死亡承诺后allatectomy的四龄幼虫，一个程序，诱导早熟PCD。定时应用JHA和在JHA存在下用20 E培养ASG表明，在切除全侧的幼虫中，在过早的肠道净化之前，ASG在切除全侧的72和96 h之间（即24-48 μ l）失去了对JHA的敏感性。这一结果与五龄幼虫的结果相似。我们的结论是，细胞死亡的承诺发生在ASG成为有能力响应20 E的前一天。(C)2004 Elsevier Ltd.保留所有权利。
The insect steroid hormone, 20-hydroxyecdysone (20E) triggers the programmed cell death (PCD) of the anterior silk glands (ASGs) of the silkworm, Bonibyx mori. We tried to determine the time of commitment to die (death commitment) by examining ASG responses to 20E and juvenile hormone analogue (JHA) in vivo as well as in vitro. The ASGs obtained late on day 6 of the fifth instar completed PCD when cultured with 20E, while the ASGs obtained on day 4 and cultured with 20E did not undergo PCD. The ASGs became competent to respond to 20E at mid-day 5. The ASGs with responsiveness to 20E were not sensitive to JHA, indicating that the ASGs were committed to die before becoming capable of responding to 20E. Topical application of JHA on day 4 suppressed 20E-induced PCD, but that on day 5 failed to do so, indicating that the death commitment might occur between day 4 and 5. We also determined the time of death commitment after allatectomy of the fourth instar larvae, a procedure that induced the precocious PCD. Timed application of JHA and culture of ASGs with 20E in the presence of JHA showed that the ASGs had lost their sensitivity to JHA between 72 and 96 h after allatectomy, i.e. 24-48 It before precocious gut purge in the allatectomized larvae. This result is similar to that obtained in the fifth instar. We conclude that the cellular commitment to die takes place one day before the ASGs become competent to respond to 20E. (C) 2004 Elsevier Ltd. All rights reserved.