Three-dimensional reconstruction of the nose epidermal cells in the microbial feeding nematode, Acrobeles complexus (Nematoda: Rhabditida)
Three-dimensional reconstruction of the nose epidermal cells in the microbial feeding nematode, Acrobeles complexus (Nematoda: Rhabditida)
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DOI：
10.1002/jmor.10456
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发表时间：
2006-11-01
影响因子：
1.5
通讯作者：
Baldwin, James G.
中科院分区：
文献类型：
--
作者：
Bumbarger, Daniel J.;Crum, John;Baldwin, James G.
线虫前端（鼻）表皮在线虫的进化、发育和功能性取食形态中起着重要作用，但关于这一复杂器官系统的信息有限。在这里，我们制作了一个由13个细胞组成的器官系统的3D模型，这些细胞是由微生物摄食线虫的一系列透射电子显微照片重建的。发现鼻表皮细胞在核的数量和排列上与远亲模式生物秀丽隐杆线虫大致相似，这些细胞主要是合胞细胞；这种相似性证明了惊人的进化守恒，这使得在分类群之间有了强有力的同源性陈述。然而，研究细胞形状的细节揭示了令人惊讶的复杂的亚细胞特化，这与秀丽隐杆线虫在细胞过程的数量和排列上明显不同。前拱廊、后拱廊和HypB合胞体的前环突在唇问题的底部形成巢状复合体。HypC的前环突和内唇窝细胞与头问题的基部和径向脊突有关。细胞外细丝（肌腱器官）和辐射细胞骨架。后拱廊合胞体的纤维在体壁肌肉细胞和咽之间形成连接。鉴定了一种在其他线虫中没有已知同源物的表皮细胞。研究结果为头蝽科（包括肢肢科）特殊取食附属物（probolae）的发育和进化起源提供了假设基础，并对密切相关的主要植物寄生类群鼻表皮细胞的同源性假设进行了修正。
The epidermis of the anterior end (nose) plays an important role in the evolution, development, and functional feeding morphology in nematodes, but information on this complex organ system is limited. Here, we produce a 3D model of 13 of the cells making up this organ system reconstructed from serial transmission electron micrographs of the microbial feeding nematode, Acrobeles complexus. Nose epidermal cells were found to be broadly similar to those of the distantly related model organism Caenorhabditis elegans in the number and arrangement of nuclei in these largely syncytial cells; this similarity demonstrates striking evolutionary conservation that allows for robust statements of homology between the taxa. Examining details of cell shape, however, revealed surprisingly complex subcellular specialization, which differed markedly from C. elegans in the number and arrangement of cell processes. Anterior toroid processes of the anterior arcade, posterior arcade, and HypB syncytia form a nested complex at the base of the labial probolae. Anterior toroid processes of HypC and the inner labial socket cells are associated with the base of the cephalic probolae and radial ridge processes. Extracellular filaments (tendon organs) and radiating cytoskeletal. filaments of the posterior arcade syncytium form a connection between the body wall muscle cells and the pharynx. An epidermal cell with no known homolog in other nematodes is identified. Findings provide a basis to propose hypotheses related to the development and evolutionary origin of specialized feeding appendages (probolae) in the Cephalobinae (including Acrobeles), and hypotheses of homology are revised for epidermal cells in the nose of the closely related and primarily plant parasitic group.