Apoptosis and cell proliferation in the Xenopus small intestine during metamorphosis
Apoptosis and cell proliferation in the Xenopus small intestine during metamorphosis
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DOI：
10.1007/s004410050716
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发表时间：
1996-12-01
影响因子：
3.6
通讯作者：
Ueda, S
中科院分区：
文献类型：
--
作者：
IshizuyaOka, A;Ueda, S
在两栖动物小肠中，上皮从幼虫型向成虫型的转变主要是幼虫上皮退化和新（成虫）上皮发育的结果。在细胞水平的分析中，我们按时间顺序检查细胞凋亡和细胞增殖在爪蟾肠使用原位缺口末端标记的基因组DNA（TUNEL）和溴脱氧尿苷（BrdU）免疫组化。在变态前和变态前期，TUNEL检测到少量凋亡细胞，BrdU标记了少量随机分布在幼虫上皮中的增殖细胞。在变态高潮的开始，当第一次检测到成体上皮的原基时，凋亡细胞的数量突然增加，而增殖细胞的数量只在成体上皮中增加。随后，发生了一个戏剧性的细胞损失的幼虫上皮和成人上皮的快速增长。在完全上皮替换后，成体上皮分化成具有类似于哺乳动物肠上皮的细胞更新系统的单层柱状上皮。这些结果表明，幼虫上皮细胞凋亡的进展，同时与成人上皮细胞的活跃增殖的早期阶段的变态高潮，这与修改的基底膜内衬两种类型的上皮细胞。
In the amphibian small intestine, the epithelial transformation from the larval to adult type is mainly the result of degeneration of the larval epithelium and development of the new (adult) epithelium. In this analysis at the cellular level, we chronologically examined apoptosis and cell proliferation in the Xenopus intestine by using in situ nick end-labeling of genomic DNA (TUNEL) and bromodeoxyuridine (BrdU) immunohistochemistry. During pre- and prometamorphosis, few apoptotic cells were detected by TUNEL, and a small number of proliferating cells randomly distributed in the larval epithelium were labeled by BrdU. At the beginning of the metamorphic climax, when primordia of the adult epithelium were first detected, numbers of apoptotic cells suddenly increased in the larval epithelium, whereas numbers of proliferating cells increased only in the adult epithelium. Subsequently, a dramatic cell loss of the larval epithelium and a rapid growth of the adult epithelium occurred. Following complete epithelial replacement, the adult epithelium became differentiated into a simple columnar epithelium possessing a cell renewal system similar to that of mammalian intestinal epithelium. These results indicate that larval epithelial apoptosis progresses simultaneously with active proliferation of the adult epithelium during the early period of metamorphic climax, which coincides with the modification of the basement membrane lining both types of epithelia.