Regulation of vitellogenesis in ticks and purification of vitellogenesis inducing factor.

研究了软蜱、莫瓦鸟和白斑鸟卵黄蛋白的生物合成及其激素调控。首先从蜱的新卵和血淋巴中分别纯化和鉴定了蛋黄蛋白卵黄蛋白（Vn）和卵黄蛋白前体血淋巴蛋白卵黄蛋白（Vg）。我们证明了Vn和Vg是一种与血红素和脂质非共价结合的磷酸化糖蛋白，其天然分子大小约为600 kD，由6个多肽组成。Vg在脂肪体中合成，分泌到血淋巴中，并以Vn的形式积累到发育中的卵母细胞中。Vn由6个不同于（更小）Vg的多肽组成。脂肪体中的Vg合成主要是由充盈刺激激活的。血餐后Vg在充血后第2天首先出现在血淋巴中，并在血淋巴中浓度升高至非常高（最高60，mugl, mul）。我们尝试用pr . More ecocene来研究激素诱导Vg合成的方法来培育无激素蜱。我们不能成功地培育出这些动物，但我们知道，在低剂量（少于100杯/只蜱）下，这种蜱的早熟没有影响，而在高剂量（超过150杯/只蜱）下，这种蜱是有毒的。但我们发现其中一种人工拟除虫菊酯类杀虫剂氯氰菊酯（CyM）对未充血的雌成虫，甚至对未充血的雄成虫和若虫都有诱导Vg合成和卵巢发育的积极作用。CyM处理的未充血雌性产生Vg并发育卵巢（但卵子较少）。这意味着如果给予适当的体液条件，未充血的雌性有能力产生Vg。我们将几种天然幼崽激素（JH）和JH类似物（JHA）应用于未充血雌性，但对卵黄形成没有积极的影响。因此我们认为JH不参与膨胀后诱导Vg合成的过程。从神经激活拟除虫菊酯（CyM）可诱导卵黄原蛋白合成的事实出发，并从结联实验中发现，在脂肪体中，synganglion （SyG）具有诱导卵黄原蛋白合成的因子。我们发现，未充血的雌性小鼠用从未充血的雌性小鼠身上采集的联神经节提取物处理后产生的Vg浓度显著高于蜱林格处理的动物。我们对该卵黄生成诱导因子（VIF）进行了纯化，结果表明VIF是一种多肽。少

Biosynthesis of yolk protein and its hormonal regulation were investigated in the soft tick, Ornithodoros mouvata and Ornithodoros parkeri. We first purified and characterized yolkk protein, vitellin (Vn), and the hemolymph precursor of Vn, vitellogenein (Vg) from newly laid eggs and hemolymph of the tick, respectively. we demonstrated Vn and Vg are a conjugated phospho-glycoprotein associated non-covalently with haem and lipid, which molecular size is about 600 kD as native and is composed 6 polypeptides. Vg is synthesized in the fat body, secreted into hemolymph and accumulated into the developing oocytes as Vn. Vn is composed of 6 polypeptides differnt (more smaller) from that of Vg. Vg synthesis in the fat body is primarily activated by the stimulation of engorgement. After blood meal Vg appear in the hemolymph first on day 2 after engorgement and increased to very high concentration in the hemolymph (maximum 60, mugl, mul). We have tried to produce a hormone free ticks by using pr … More ecocene to study hormonal induction of Vg synthesis. We could- not produce those animals successfully, but 'we knew that precocene has no effect in lower doses (less than 100 mug/tick) and toxic in higher doses (more than 150 mug/tick) in this species of tick. But we found that one of synthetic pyrethroid, cypermethrin (CyM) has a positive effect to induce Vg synthesis and ovarian development in unengorged (both mated and virgin) adult females, and also even unengorged males and nymphs. CyM treated unengorged females produced Vg and developed ovary (but fewer eggs). This meant that unengorged females have ability to produce Vg if given a proper humoral conditions. We applied several natural juvenile hormones (JH) and JH analogs (JHA) on unengorged females, but we could not get positive effects for vitellogenesis. Therefore we concluded JH is not involved in the course of Vg synthesis induction after engorgement. From the fact that nerve activating pyrethroid, CyM, can induce vitelogenin synthesis, and from some ligation experiments we showed synganglion (SyG) has a factor which induces Vg synthesis in the fat body. We showed unengorged females treated with extract of synganglions collected from unengorged females produced Vg in significantly higher concentration than tick Ringer treated animals. We tried to purify this vitellogenesis inducing factor (VIF) and showed VIF is a polypeptids. Less