DEVELOPMENTAL ALTERATIONS IN SENSORY NEUROANATOMY OF THE CAENORHABDITIS-ELEGANS DAUER LARVA
DEVELOPMENTAL ALTERATIONS IN SENSORY NEUROANATOMY OF THE CAENORHABDITIS-ELEGANS DAUER LARVA
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DOI：
10.1002/cne.902190407
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发表时间：
1983-01-01
影响因子：
2.5
通讯作者：
RIDDLE, DL
中科院分区：
文献类型：
--
作者：
ALBERT, PS;RIDDLE, DL
结果表明，C.在几个标本中检查了秀丽线虫Dauer幼虫，并与Dauer阶段之前的第2阶段（L2）幼虫进行了比较。在某些情况下，与L3，Postdauer L4和成人阶段进行比较。而在不同的nondauer阶段的感觉结构密切相似，dauer幼虫不同的某些化学和机械感觉器官，包括内唇感器，端足和deirids。与L2和PostdauerL 4阶段相比，Dauer阶段两种类型的内阴唇神经元的传入尖端的相对位置是颠倒的。内唇神经元1比神经元2在6个感受器中的位置更靠前，且神经元1的尖端增大。神经元2纤毛长度仅为L2纤毛的1/3。在dauer期，端生神经元c、d、g、i和端生鞘细胞的形态和位置发生改变。神经元g和i在dauer外板通道内向后移位。神经元d有显着更多的微绒毛突起比d细胞在L2，L3或postdauer L4幼虫。Dauer神经元c的翼状突起形成200 °- 240.degree.横切面呈弧形，包括2个细胞的广泛重叠。L2中的弧很少跨越> 100 °。并且不发生重叠。而L2幼虫具有两个独立的两侧外生鞘细胞，左，右鞘细胞往往是连续的dauer幼虫。Deirid感觉树突表现出一个dauer特定的结构和方向。每个神经元的尖端通过在L2或postdauer L4阶段中未观察到的子结构附着于体壁角质层;神经元的方向平行于dauer幼虫的纵轴。在其他阶段，表皮感觉末梢垂直于角质层。可逆的神经结构的变化进行了讨论的背景下，dauer特定的行为。
The anterior sensory ultrastructure of the C. elegans dauer larva was examined in several specimens and compared with that of the 2nd-stage (L2) larva, which immediately precedes the dauer stage. In some instances comparisons were made with L3, postdauer L4 and adult stages. Whereas sensory structures in different nondauer stages closely resemble each other, the dauer larva differs in certain chemosensory and mechanosensory organs including the inner labial sensilla, amphids and deirids. The relative positions of the afferent tips of the 2 types of inner labial neurons are reversed in the dauer stage compared to the L2 and postdauer L4 stages. Inner labial neuron 1 rather than neuron 2 is more anterior in each of he 6 sensilla and neuron 1 had an enlarged tip. The neuron 2 cilia are only 1/3 as long as those in the L2. Amphidial neurons c, d, g and i and the amphidial sheath cell are altered in shape or position in the dauer stage. Neurons g and i are displaced posteriorly within the dauer amphidial channel. Neuron d has significantly more microvillar projections than do the d cells in L2, L3 or postdauer L4 larvae. Winglike processes of dauer neuron c form a 200.degree.-240.degree. arc in transverse section, including extensive overlap of the 2 cells. The arc in an L2 seldom spans > 100.degree. and overlap does not occur. While L2 larvae possess 2 separate bilateral amphidial sheath cells, the left and right sheath cells are often continuous in the dauer larva. Deirid sensory dendrites exhibit a dauer-specific structure and orientation. The tip of each neuron is attached to the body wall cuticle by a substructure not observed in L2 or postdauer L4 stages; the neurons are oriented parallel to the longitudinal axis of the dauer larva. The deirid sensory terminals are oriented perpendicular to the cuticle in other stages. Reversible alterations in neural structure are discussed in the context of dauer-specific behavior.