The neurons of class ALD mediate thermotaxis in the parasitic nematode, Strongyloides stercoralis
The neurons of class ALD mediate thermotaxis in the parasitic nematode, Strongyloides stercoralis
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DOI：
10.1016/s0020-7519(00)00087-4
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发表时间：
2000-09-01
影响因子：
4
通讯作者：
Schad, GA
中科院分区：
文献类型：
--
作者：
Lopez, PM;Boston, R;Schad, GA
粪类圆线虫，一种寄生于恒温动物的皮肤穿透线虫，向温暖的地方迁移。在线虫中，端足动物，位于前部，成对的感受器，每个都包含一束感觉神经元。在自由生活的线虫秀丽隐杆线虫的端头动物中，一对神经元，每个神经元的末端都有一簇微绒毛样突起，被称为初级温度感受器，并被命名为指细胞（AFD类）。在寄生虫捻转血矛线虫（Haemonchus contortus）的端头动物中，也有一对类似的神经元具有温度感应功能。粪类圆线虫缺乏指细胞，但在其端肢中，它有一对神经元，其树突终止于多层复合体的板层细胞，即所谓的板层细胞（ALD类）。因此，有人推测，这些板层细胞可能介导趋热性的皮肤穿透感染幼虫的这个物种。为了研究这一点，第一阶段S。麻醉粪蝇幼虫，用激光微束消融成对的ALD类神经元。然后将幼虫培养至感染性第三阶段（L3），并在温度梯度上测定趋热性。与对照组相比，具有消融ALD类神经元对的L3显示出显著降低的趋热性。ALD类神经元的温度感受功能（i）将该神经元对与S.（ii）与C.优雅的。ALD神经元的结构和位置特征表明，这些神经元实际上可能与C. elegans，而其花的发展和热敏功能建议的同源性指细胞（AFD）的线虫。(C)2000年澳大利亚寄生虫学会由爱思唯尔科技有限公司出版。保留所有权利。
Strongyloides stercoralis, a skin-penetrating nematode parasite of homeotherms, migrates to warmth. In nematodes, the amphids, anteriorly positioned, paired sensilla, each contain a bundle of sensory neurons. In the amphids of the free-living nematode Caenorhabditis elegans, a pair of neurons, each of which ends in a cluster of microvilli-like projections, are known to be the primary thermoreceptors, and have been named the finger cells (class AFD). A similar neuron pair in the amphids of the parasite Haemonchus contortus is also known to be thermosensory. Strongyloides stercoralis lacks finger cells but, in its amphids, it has a pair of neurons whose dendrites end in a multi-layered complex of lamellae, the so-called lamellar cells (class ALD). Consequently, it was hypothesised that these lamellar cells might mediate thermotaxis by the skin-penetrating infective larva of this species. To investigate this, first stage S. stercoralis larvae were anaesthetised and the paired ALD class neurons were ablated with a laser microbeam. The larvae were then cultured to the infective third stage (L3) and assayed for thermotaxis on a thermal gradient. L3 with ablated ALD class neuron pairs showed significantly reduced thermotaxis compared with control groups. The thermoreceptive function of the ALD class neurons (i) associates this neuron pair with the host-finding process of S. stercoralis and (ii) demonstrates a functional similarity with the neurons of class AFD in C. elegans. The structural and positional characteristics of the ALD neurons suggest that these neurons may, in fact, be homologous with one pair of flattened dendritic processes known as wing cells (AWC) in C. elegans, while their florid development and thermosensory function suggest homology with the finger cells (AFD) of that nematode. (C) 2000 Australian Society for Parasitology Inc. Published by Elsevier Science Ltd. All rights reserved.