Diversity of biological clocks in the tidal environment : molecular mechanism

河口蟹的卵附着系统是在产卵后在母体卵毛上形成的，在孵化后从母体卵毛上脱落。脱毛是由一种活性因子引起的，我们称之为OHSS（卵生脱毛物质），它在胚胎孵化时释放出来。经纯化后，其活性形态的分子量为25 kDa。从胚胎cDNA文库中克隆的OHSS cDNA长1759，在一个开放阅读框（ORF）中编码492个氨基酸。预测蛋白的c端部分由胰蛋白酶样丝氨酸蛋白酶结构域组成，与其他动物的同源性为33-38%。作为酶原分泌的预测蛋白（54.7 kDa）可能在翻译后被切割，将c端与n端区分离。两年前，我们发现了河口蟹孵化的奇妙现象。为了研究十足甲壳类动物的孵化机制，我们尝试使用多种化学物质诱导孵化。几乎化学物质都是无效的，但他发现只有丙酮和乙腈溶液能导致胚胎孵化。在加气对照水（400 ~ 500 ml， 5‰的人工海水）下孵化，无胚离体。丙酮作用10 min后约49 h开始孵化，55 h后孵化率达到最大值。所有经丙酮处理的幼体都能游动，其行为与从雌性释放的幼体完全相同。丙酮浓度不同，孵化率有很大差异。95%的胚胎在丙酮浓度为60%的情况下孵化，87%的胚胎在丙酮浓度为80%的情况下孵化。因此，估计60%丙酮溶液的孵化率最大。在本研究的第一步，我们认为S. haematocheir胚胎的孵化可能是由丙酮等物质引起的。孵化肯定是由雌性释放的一种活跃因子引起的。但许多实验表明，孵化诱导物质与乙酰胶等化学物质有很大不同。我们正在分析这种物质。少

The egg attachment system of an estuarine crab Sesarma haematocheir is formed on the maternal ovigerous hairs just after egg-laying, and slips off these hairs just after hatching. The stripping is caused by an active factor that we call OHSS (ovigerous-hair stripping substance), which is released by the embryo upon hatching.OHSS was purified, and its active form had a molecular mass of 25 kDa. The cDNA of OHSS cloned from an embryonic cDNA library was 1759 by long, encoding 492 amino acids in a single open reading frame (ORF). The C-terminal part of the predicted protein was composed of a trypsin-like serine protease domain, with homology to counterparts in other animals of 33-38%. The predicted protein (54.7 kDa) secreted as a zymogen may be cleaved post-translationally, separating the C-terminal from the N-terminal region.Two years before, we found fantastic phenomena about hatching of an estuarine crab. To investigate mechanisms of hatching in decapod crustaceans, we tried to induce … More hatching by use of many kinds of chemicals. Almost chemicals are ineffective, but he found that only acetone and acetonitrile solutions can cause hatching of embryos. No embryos detached from the female hatched under the control water with aeration (400-500 ml of 5‰ artificial seawater). Hatching started around 49 hrs after the treatment with acetone for 10 min, and hatching ratio attained maximum 55 hrs after. All zoeas treated with acetone swam, and their behavior was completely the same as zoeas released from the female.The ratio of hatching was largely different according to the concentration of acetone. Ninety-five percent hatched among the embryos treated with 60% acetone, and 87% hatched among those treated with 80% acetone. Thus, the solution of 60% acetone was estimated to cause maximum ratio of hatching.At the first step of this study, we thought that hatching of S. haematocheir embryos could be caused by a substance such as acetone. Hatching is certainly caused by an active factor released from the female. But many experiments suggested that the hatching inducing substance is largely different from a chemical such as acetolie. We are analyzing this substance. Less