DAUERLARVA, A POST-EMBRYONIC DEVELOPMENTAL VARIANT OF NEMATODE CAENORHABDITIS-ELEGANS
DAUERLARVA, A POST-EMBRYONIC DEVELOPMENTAL VARIANT OF NEMATODE CAENORHABDITIS-ELEGANS
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DOI：
10.1016/0012-1606(75)90109-8
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发表时间：
1975-01-01
影响因子：
2.7
通讯作者：
RUSSELL, RL
中科院分区：
文献类型：
--
作者：
CASSADA, RC;RUSSELL, RL
在自由生活的线虫秀丽隐杆线虫的胚胎后发育过程中，可能会出现一个形态上可识别的非生长阶段，称为“dauerlarva”。通过使用同步种群以及生长和蜕皮，研究表明，幼虫是在生命周期的特定点（四次角质层蜕皮中的第二次）发生兼性、可逆的停滞而形成的，以响应外部条件。在每次蜕皮时，正常动物都会经历“嗜睡”阶段，在这个阶段中，进食和运动会暂时停止。在道幼虫阶段，摄食无限期地停止并且运动显着减少。基于 Dauerlarvae 对十二烷基硫酸钠 (SDS) 的特殊抗性，开发了一种简单的定量测定法来研究 Dauerlarva 的形成及其逆转。 dauerlarvae 的 SDS 抗性需要不进食和特别不渗透的角质层。通过限制细菌浓度（食物供应）可以有效诱导道幼虫形成，但不能通过完全饥饿来诱导。通过转移到含有过量细菌的新鲜培养基中可以诱导数量恢复到正常发育。更简单的刺激可以以更慢的速度引起恢复，除了营养之外的主要因素是营养是最佳离子和渗透条件以及动物的非抑制浓度。恢复有几个可识别的阶段，从恢复进食开始。角质层在超微结构上与正常角质层非常不同，在下一次蜕皮时脱落，之后发育正常。描述了一种温度敏感突变体，尽管存在丰富的食物，但它在高温下形成 Dauerlarvae，并讨论了 Dauerlarvae 用于进一步突变体分离的用途。
In the postembryological development of the free-living nematodeCaenorhabditis elegans, a morphologically recognizable, nongrowing stage, called the dauerlarva, may arise. Using synchronous populations and following growth and molting, it has been shown that the dauerlarva is formed by a facultative, reversible arrest at a specific point in the life cycle, the second of four cuticle molts, in response to external conditions.At each molt a normal animal passes through “lethargus,” a stage in which feeding and locomotion are transiently arrested. In the dauerlarva stage, feeding is arrested indefinitely and locomotion is markedly reduced. A simple quantitative assay, based on the exceptional resistance of dauerlarvae to sodium dodecyl sulfate (SDS), has been developed to study dauerlarva formation and its reversal. The SDS resistance of dauerlarvae requires both non-feeding and an especially impermeable cuticle. Dauerlarva formation can be efficiently induced by limiting the concentration of bacteria (the food supply), but not by complete starvation. Quantitative recovery to normal development can be induced by transfer to fresh medium with excess bacteria. Simpler stimuli can elicit recovery at slower rates, the principal factors besides nutrition being nutrition being optimal ionic and osmotic conditions and a noninhibitory concentration of animals. There are identifiable stages in recovery, beginning with a resumption of feeding. The cuticle, ultrastructurally very different from normal cuticle, is shed at the next molt, after which development appears normal. A temperature-sensitive mutant, which forms dauerlarvae at high temperature despite the presence of abundant food, is described, and the use of dauerlarvae for further mutant isolation is discussed.