Riley L G, Tsukimura B
Department of Biology, California State University, Fresno 93740, USA.
J Exp Zool. 1998 Jun 15;281(3):238-47.
Investigation of reproductive control within the tadpole shrimp, Triops longicaudatus, required the isolation and characterization of the yolk protein (vitellin, Vn). To this end, tadpole shrimp were cultured in environmental chambers (29 degrees C-22 degrees C, with 14:10 light:dark cycle). Desiccated cysts hatched in 2-3 days after inundation. The tadpole shrimp began egg deposition 7 to 8 days after hatching and exhibited a mean growth rate of 1.85 +/- 0.24 mm/day. It was observed that 4-day-old shrimp had visible eggs in their ovaries. In addition, Vn was isolated and characterized from reproductive animals, resolving as one protein on native PAGE, and possessing a molecular weight (MW) of 376,000 +/- 2,900 as determined by FPLC. Examination by SDS-PAGE revealed that Vn is composed of a single molecule with a MW of 214,000 +/- 2,000. Methyl farnesoate (MF), a crustacean compound whose role in reproduction is still being elucidated and is structurally similar to juvenile hormone III (JH III) was incubated with ovarian explants. These explants were incubated for 24 h at room temperature in EAGLE's medium adjusted to Van Harreveld's solution in six concentrations (1 pM to 100 nM) of MF and JH III. Methyl farnesoate and JH III had no direct in vitro effect on yolk protein synthesis (P < or = 0.545 and P < or = 0.815, respectively).
对长尾鲎虫（Triops longicaudatus）生殖调控的研究需要分离并鉴定其卵黄蛋白（卵黄磷蛋白，Vn）。为此，将鲎虫置于环境箱中培养（29摄氏度至22摄氏度，光照与黑暗周期为14:10）。干燥的卵囊在浸水后2至3天孵化。鲎虫在孵化后7至8天开始产卵，平均生长速率为1.85±0.24毫米/天。观察到4日龄的鲎虫卵巢中有可见的卵。此外，从生殖期动物中分离并鉴定了Vn，在非变性聚丙烯酰胺凝胶电泳（native PAGE）上显示为一种蛋白质，通过快速蛋白质液相色谱（FPLC）测定其分子量（MW）为376,000±2,900。十二烷基硫酸钠-聚丙烯酰胺凝胶电泳（SDS-PAGE）分析表明，Vn由单一分子组成，分子量为214,000±2,000。将法尼酸甲酯（MF），一种在生殖中作用仍在阐明且结构与保幼激素III（JH III）相似的甲壳类化合物，与卵巢外植体一起孵育。这些外植体在室温下于调整为范哈雷维尔德溶液的伊格尔培养基中，以六种浓度（1皮摩尔至100纳摩尔）的MF和JH III孵育24小时。法尼酸甲酯和JH III对卵黄蛋白合成无直接体外作用（P≤0.545和P≤0.815，分别）。
