Key Laboratory of Plant Protection Resources and Pest Management, Ministry of Education, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi 712100, China.
Key Laboratory of Plant Protection Resources and Pest Management, Ministry of Education, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi 712100, China.
Arthropod Struct Dev. 2024 Sep;82:101383. doi: 10.1016/j.asd.2024.101383. Epub 2024 Sep 6.
The rectum is an important part of the alimentary canal responsible for ion and water reabsorption of insects. However, it has rarely been studied in the larvae of Panorpidae, the largest family in Mecoptera. Here, we investigated the ultrastructure of larval rectum of the scorpionfly Panorpa liui Hua, 1997 using light and transmission electron microscopy. The rectum comprises tracheal muscular layers, connective tissue, non-cellular basal lamina, junctional cells, rectal epithelium, cuticle with irregular outlines, and a central lumen. The rectal epithelium is infolded to form six longitudinal rectal folds, which are distinct from rectal pads or papillae. In each rectal fold, the apical and basal plasma membranes of epithelial cells are infolded and the lateral plasma membranes form septate and scalariform junctions. The well-developed rectal folds are postulated to be closely associated with reabsorption of ions and water in the larvae. The associations of rectal folds with larval behaviors are briefly discussed in Mecoptera.
直肠是昆虫消化道的重要组成部分，负责离子和水的重吸收。然而，在长翅目最大的科——螳䗛科的幼虫中，对直肠的研究很少。本研究利用光镜和透射电镜技术，对中国螳䗛 Panorpa liui 的幼虫直肠进行了超微结构研究。直肠由气管肌层、结缔组织、无细胞基底膜、连接细胞、直肠上皮、具不规则轮廓的角质层和中央腔组成。直肠上皮内褶形成 6 条纵向直肠褶，与直肠垫或乳突不同。在每个直肠褶中，上皮细胞的顶膜和底膜内褶，侧膜形成分隔和栉状连接。推测发达的直肠褶与幼虫离子和水的重吸收密切相关。简要讨论了直肠褶与长翅目幼虫行为的关系。
