Zhang Guowei, Hua Baozhen
State Key Laboratory of Crop Stress Biology for Arid Areas, Key Laboratory of Plant Protection Resources and Pest Management, Ministry of Education, Entomological Museum, Northwest A&F University, Yangling, Shaanxi 712100, China.
State Key Laboratory of Crop Stress Biology for Arid Areas, Key Laboratory of Plant Protection Resources and Pest Management, Ministry of Education, Entomological Museum, Northwest A&F University, Yangling, Shaanxi 712100, China.
Tissue Cell. 2014 Oct;46(5):388-96. doi: 10.1016/j.tice.2014.07.002. Epub 2014 Jul 19.
Fine structure of the midgut and degeneration of the midgut epithelium of the scorpionfly Sinopanorpa tincta (Navás) adults were investigated using light microscopy and scanning and transmission electron microscopy. The results show that the tubular midgut lacks gastric caeca and is composed of an outer longitudinal and an inner circular muscle layer, a basal lamina, an epithelium and a lumen from the outside to inside. A peritrophic membrane was not found in the lumen. A mass of nodules was observed on the surface of the basal lamina. Three types of cells were recognized in the epithelium: digestive, secretory, and regenerative cells. The digestive cells contain irregular-shaped infoldings in the basal membrane and two types of microvilli in the apical membrane. The secretory cells are characterized by irregular shape and large quantities of secretory granules in the basal cytoplasm. The regenerative cells are triangular in shape and distributed only in the nodules. The epithelial cells are degenerated through programmed cell-death mechanisms (apoptosis and necrosis). The type, function, and degeneration of the epithelial cells of the midgut are briefly discussed.
利用光学显微镜、扫描电子显微镜和透射电子显微镜，对蝎蛉（Sinopanorpa tincta (Navás)）成虫中肠的精细结构及中肠上皮细胞的退化进行了研究。结果表明，管状中肠无胃盲囊，从外到内由外层纵肌层、内层环肌层、基膜、上皮细胞层和管腔组成。管腔内未发现围食膜。在基膜表面观察到大量结节。上皮细胞层可识别出三种类型的细胞：消化细胞、分泌细胞和再生细胞。消化细胞的基膜有不规则形状的内褶，顶膜有两种类型的微绒毛。分泌细胞形状不规则，基部细胞质中有大量分泌颗粒。再生细胞呈三角形，仅分布于结节中。上皮细胞通过程序性细胞死亡机制（凋亡和坏死）发生退化。对中肠上皮细胞的类型、功能及退化进行了简要讨论。
