Shinohara Yoshiyasu, Ishii Naohito, Takahashi Shinichiro, Okazaki Toshio
Department of Hematological Informatics, Kitasato University, School of Allied Health Science, 1-15-1 Kitasato, Sagamihara 228-8555, Japan.
Zoolog Sci. 2008 Feb;25(2):139-45. doi: 10.2108/zsj.25.139.
To study midgut degradation and programmed cell death, we performed methyl green-pyronin staining and Giemsa staining of the midgut of silkworms during metamorphosis. Midgut epithelial cells underwent pyknosis and cytoplasmic shrinkage on the second day of spinning. In the prepupal stage, all midgut epithelial cells desquamated into the midgut lumen, rapidly forming apoptotic bodies. The number of apoptotic bodies in the midgut decreased rapidly from the prepupal stage to the third day of the pupal stage. DNA fragmentation at the time of apoptotic body formation was confirmed by the comet assay. In the midgut lumen from the prepupal stage to the first through third days of the pupal stage in which apoptotic bodies were observed, granular cells were present. Their morphology was similar to that in the body fluid and, during the pupal stage, intracellular granules increased in size and number with time, giving the appearance of a foamy cell. In this stage, numerous granular cells were observed under the basement membrane of the midgut, and phagocytosed apoptotic bodies were seen within granular cells in the midgut lumen. Granular cells may be actively involved in the clearance of apoptotic bodies from the midgut during larval-pupal ecdysis.
为了研究中肠降解和程序性细胞死亡，我们在变态过程中对家蚕中肠进行了甲基绿-派洛宁染色和吉姆萨染色。吐丝第二天，中肠上皮细胞发生核固缩和细胞质收缩。在预蛹期，所有中肠上皮细胞脱落到中肠腔中，迅速形成凋亡小体。从中肠上皮细胞凋亡小体形成时的DNA片段化，通过彗星试验得到证实。在从中肠上皮细胞凋亡小体形成时的DNA片段化，通过彗星试验得到证实。在从中肠上皮细胞凋亡小体形成时的DNA片段化，通过彗星试验得到证实。在从中肠上皮细胞凋亡小体形成时的DNA片段化，通过彗星试验得到证实。在从中肠上皮细胞凋亡小体形成时的DNA片段化，通过彗星试验得到证实。在从中肠上皮细胞凋亡小体形成时的DNA片段化，通过彗星试验得到证实。在从中肠上皮细胞凋亡小体形成时被观察到的预蛹期到蛹期第一天至第三天的中肠腔中，存在颗粒细胞。它们的形态与体液中的相似，并且在蛹期，细胞内颗粒的大小和数量随时间增加，呈现出泡沫细胞的外观。在这个阶段，在中肠基底膜下观察到大量颗粒细胞，并且在中肠腔的颗粒细胞内可见吞噬的凋亡小体。颗粒细胞可能在幼虫-蛹蜕皮期间积极参与从中肠清除凋亡小体。
