Division of Biological Sciences Tucker Hall, University of Missouri, 65211, Columbia, Missouri.
J Chem Ecol. 1984 Aug;10(8):1265-80. doi: 10.1007/BF00988553.
The free-living soil nematodeCaenorhabditis elegans forms a nonfeeding dispersal stage at the second molt called the dauer larva when exposed to environmental cues indicating crowding and limited food. An improved bioassay, tenfold more sensitive than that used previously, has been used in the characterization of the two chemical cues which act competitively in controlling this developmental process. The pheromone concentration provides a measure of the population density; it enhances dauer larva formation, and inhibits recovery (exit) from the dauer stage. The pheromone is a family of related molecules which are nonvolatile, very stable, and possess physical and Chromatographie properties similar to those of hydroxylated fatty acids and bile acids. A food signal, with effects on development opposite those of the pheromone, is produced by bacteria, and is also present in yeast extract. In contrast to the pheromone, the food signal is a labile substance which is neutral and hydrophilic.
自由生活的土壤线虫秀丽隐杆线虫在暴露于指示拥挤和有限食物的环境线索时，会在第二次蜕皮时形成非摄食的分散阶段，称为 dauer 幼虫。一种比以前使用的生物测定法灵敏十倍的改良生物测定法已被用于描述两种化学线索，这两种化学线索在控制这一发育过程中具有竞争性。信息素浓度提供了种群密度的衡量标准；它增强 dauer 幼虫的形成，并抑制从 dauer 阶段的恢复（退出）。信息素是一系列相关分子，它们是非挥发性的，非常稳定的，并且具有与羟基脂肪酸和胆汁酸相似的物理和色谱性质。一种食物信号，其对发育的影响与信息素相反，由细菌产生，也存在于酵母提取物中。与信息素相反，食物信号是一种不稳定的物质，呈中性和亲水。
