Oeh U, Lorenz M W, Dyker H, Lösel P, Hoffmann K H
Lehrstuhl Tierökologie I, Universität Bayreuth, D-95440, Bayreuth, Germany.
Insect Biochem Mol Biol. 2000 Aug-Sep;30(8-9):719-27. doi: 10.1016/s0965-1748(00)00043-6.
A peptide that strongly stimulates juvenile hormone (JH) biosynthesis in vitro by the corpora allata (CA) was purified from methanolic brain extracts of adult Spodoptera frugiperda. Using HPLC separation followed by Edman degradation and mass spectrometry, the peptide was identified as Manduca sexta allatotropin (Mas-AT). Treating the CA from adult S. frugiperda with synthetic Mas-AT (at 10(-6) M) caused an up to sevenfold increase in JH biosynthesis. The stimulation of JH synthesis was dose-dependent and reversible. Synthetic M. sexta allatostatin (Mas-AS) (10(-6) M) did not affect the spontaneous rate of JH secretion from CA of adult S. frugiperda, nor did any of the allatostatins of the Phe-Gly-Leu-amide peptide family tested. However, when CA had been activated by Mas-AT (10(-6) M), addition of synthetic Mas-AS (10(-6) M) reduced JH synthesis by about 70%. This allatostatic effect of Mas-AS on allatotropin-activated glands was also reversible. When CA were incubated in the presence of both Mas-AT (10(-6) M) and various concentrations of Mas-AS (from 10(-8) to 10(-5) M), the stimulation of JH-biosynthesis observed was inhibited in a dose-dependent manner. The experiments demonstrate a novel mechanism of allatostatin action. In S. frugiperda JH synthesis was inhibited only in those glands which had previously been activated by an allatotropin.
从成年草地贪夜蛾的甲醇脑提取物中纯化出一种能在体外强烈刺激咽侧体（CA）合成保幼激素（JH）的肽。通过高效液相色谱分离，随后进行埃德曼降解和质谱分析，该肽被鉴定为烟草天蛾促咽侧体素（Mas-AT）。用合成的Mas-AT（10⁻⁶ M）处理成年草地贪夜蛾的CA，可使JH生物合成增加多达7倍。JH合成的刺激是剂量依赖性的且可逆。合成的烟草天蛾咽侧体抑制素（Mas-AS）（10⁻⁶ M）不影响成年草地贪夜蛾CA的JH自发分泌率，所测试的苯丙氨酸-甘氨酸-亮氨酸酰胺肽家族的任何一种咽侧体抑制素也无此影响。然而，当CA被Mas-AT（10⁻⁶ M）激活后，添加合成的Mas-AS（10⁻⁶ M）可使JH合成减少约70%。Mas-AS对促咽侧体素激活的腺体的这种咽侧体抑制作用也是可逆的。当CA在Mas-AT（10⁻⁶ M）和各种浓度的Mas-AS（从10⁻⁸到10⁻⁵ M）存在下孵育时，观察到的JH生物合成刺激以剂量依赖性方式受到抑制。这些实验证明了咽侧体抑制素作用的一种新机制。在草地贪夜蛾中，只有那些先前已被促咽侧体素激活的腺体中的JH合成受到抑制。
