Bumbarger Daniel J, Wijeratne Sitara, Carter Cale, Crum John, Ellisman Mark H, Baldwin James G
Department of Nematology, University of California, Riverside, California 92521, USA.
J Comp Neurol. 2009 Jan 10;512(2):271-81. doi: 10.1002/cne.21882.
Amphid sensilla are the primary olfactory, chemoreceptive, and thermoreceptive organs in nematodes. Their function is well described for the model organism Caenorhabditis elegans, but it is not clear to what extent we can generalize these findings to distantly related nematodes of medical, economic, and agricultural importance. Current detailed descriptions of anatomy and sensory function are limited to nematodes that recent molecular phylogenies would place in the same taxonomic family, the Rhabditidae. Using serial thin-section transmission electron microscopy, we reconstructed the anatomy of the amphid sensilla in the more distantly related nematode, Acrobeles complexus (Cephalobidae). Amphid structure is broadly conserved in number and arrangement of cells. Details of cell anatomy differ, particularly for the sensory neurite termini. We identify an additional sensory neuron not found in the amphid of C. elegans and propose homology with the C. elegans interneuron AUA. Hypotheses of homology for the remaining sensory neurons are also proposed based on comparisons between C. elegans, Strongyloides stercoralis, and Haemonchus contortus.
头感器是线虫主要的嗅觉、化学感受和温度感受器官。其功能在模式生物秀丽隐杆线虫中已有详尽描述，但目前尚不清楚这些发现能在多大程度上推广到具有医学、经济和农业重要性的远缘线虫。目前关于解剖结构和感觉功能的详细描述仅限于那些根据近期分子系统发育研究属于同一分类科（小杆科）的线虫。我们利用连续超薄切片透射电子显微镜技术，重建了亲缘关系更远的线虫——复杂顶尾线虫（头叶科）的头感器解剖结构。头感器的结构在细胞数量和排列上大致保守。细胞解剖结构的细节存在差异，尤其是感觉神经突末端。我们发现了一种在秀丽隐杆线虫头感器中未发现的额外感觉神经元，并提出它与秀丽隐杆线虫的中间神经元AUA具有同源性。还基于秀丽隐杆线虫、粪类圆线虫和捻转血矛线虫之间的比较，对头感器中其余感觉神经元的同源性提出了假设。
