Study on the Avoidance Response in Asterina pectinifera to Solaster dawsoni

在接触之前，海星从捕食性小行星Solaster Dawsoni逃离。这种反应被称为回避反应。在海洋动物群中，海星是唯一一颗表现出回避反应的小行星。一些小行星，如Asterias Rubens，表现出逃避反应，指的是对手为了拒绝捕食而进行的物理接触。我们已经阐明了Asterias putinifera的回避反应是由S.Dawsoni的生物分子诱导的，在本研究项目中，我们旨在建立一种定量的生物测定和对与回避反应有关的生物活性物质的分离和纯化。通过测量以下指标来量化生物活性：回避反应前的滞后时间、平均回避速度和到原点的距离。每个项目用五个等级进行评价，三个项目的等级总和被归类为四种生物活性强度(+，++，+和-)。用冻融法获得的一种液体(滴液)的反应最强(+)。用Pronase E处理消除了滴液的生物活性。通过30,000次超滤，生物活性物质残留在内液中。经硫酸铵分级分离、凝胶过滤层析和高效液相色谱分离表明，果胶海棠的回避反应是由几种相对分子质量在10万左右的蛋白质类化合物引起的。据我们所知，这是第一次报道具有如此大分子量的化感物质。在上述研究过程中，我们发现果胶鱼的水族水对人手的鳞片区具有治疗和预防作用。从果胶水提物中分离得到2个多羟基甾体化合物和3个甾体皂苷(果胶皂苷A、B和C)。

Asterina pectinifera flees from the predator asteroid Solaster dawsoni before contact. This response is called an avoidance reaction. A. pectinifera is the only asteroid among marine fauna, which show the avoidance reaction. Several asteroids, such as Asterias rubens, show an escape response, which refer to the physical contact by the opponent to reject the predation.We have elucidated that the avoidance response in A. pectinifera is induced by biomolecules of S. dawsoni, and in the present research project, we aimed to develop a quantitative bioassay and isolation and purification of bioactive compounds responsible to the avoidance reaction.The bioactivity was quantified by measuring the following items : "lag time before avoidance response", "average speed of evasion", and "distance from the origin". Each item was evaluated by five grades, and the sum of grades of three items were categorized into four intensities of bioactivity (+++, ++, +, and -). A liquid (drip) obtained from S. dawsoni by freeze-thaw procedure elicited the strongest response (+++). The bioactivity of the drip was eliminated by Pronase E treatment. Bioactive substances were remained in the inner solution by the ultra filtration of 30,000. Separation by ammonium sulfate fractionation, gel filtration chromatography, and HPLC revealed that the avoidance response in A. pectinifera elicited by several proteinaceous compounds with molecular weight of around 100,000. As far as we can tell that this is the first report of allelochemicals having such larger molecular weights.In the course of the above study, we found that the aquarium water of A. pectinifera showed remedial and preventive effects on scaly area of human hands. Two polyhydroxysteroids and three steroidal saponins (pectiniosides A, B and C) were isolated as bioactive substances from the water extract of A. pectinifera.