Ectodermal interactions during neurogenesis in the glossiphoniid leech Helobdella triserialis.
Ectodermal interactions during neurogenesis in the glossiphoniid leech Helobdella triserialis.
复制标题
舌水蛭 Helobdella triserialis 神经发生过程中外胚层的相互作用。
DOI：
10.1016/0012-1606(82)90008-2
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发表时间：
1982
影响因子：
2.7
通讯作者：
Weisblat,DA
中科院分区：
文献类型：
--
作者：
Blair,SS;Weisblat,DA
采用细胞消融和细胞谱系追踪相结合的方法，研究了三色水蚤胚胎发育过程中的形态发生细胞相互作用。在早期胚胎的一侧，切除已识别的外胚层成端细胞或成端细胞前体卵裂球，通常会导致相应的对侧、未经消融的成端细胞的后代细胞后来异常迁移到胚胎的消融侧；这种异常迁移被称为“中线破坏”。观察到两种不同类型的中线破坏。交叉：在切除一个N端母细胞后，对侧N端母细胞的单个干细胞后代有时会穿过胚胎生发板的腹中线。切换：在对侧O、P或Q端粒细胞产生的干细胞前体条带消融后，有时会在生发条带的起始处切换到消融侧的生发带。交叉和交换的发生表明，特定端粒细胞的后代细胞所占据的最终位置不仅由其谱系自动决定，而且还取决于与其他细胞的相互作用。然而，水蚤胚胎中枢神经系统的中线破坏并不构成真正的调节，因为神经元恢复到消融侧伴随着非消融侧的神经元缺失。这两种截然不同的中线破坏--交叉和交换--可以用干细胞带在生发带内的相对位置和生发带形成生发板的几何特征来解释。
Morphogenetic cell interactions during development were studied by combining cell ablation and cell lineage tracing techniques in embryos of the leechHelobdella triserialis. Ablation of an identified ectodermal teloblast, or teloblast precursor blastomere, on one side of an early embryo was often found to result in the later abnormal migration of the progeny cells of the corresponding contralateral, nonablated teloblast to the ablated side of the embryo; such abnormal migration was termed “midline violation.” Two different kinds of midline violation were observed. Crossover: after ablation of an N teloblast individual stem cell progeny of the contralateral N teloblast sometimes cross the ventral midline of the germinal plate of the embryo. Switching: after ablation of an OPQ teloblast precursor bandlets of stem cells produced by the contralateral O, P, or Q teloblasts sometimes switch to the germinal band of the ablated side at the site of origin of the germinal bands. The occurrence of crossover and switching shows that the eventual site occupied by a progeny cell of a particular teloblast is not automatically determined by its lineage, but also depends on interactions with other cells. Midline violation in the leech embryo CNS does not constitute true regulation, however, since the restoration of neurons to the ablated side is accompanied by a neuron deficit on the nonablated side. The occurrence of the two distinct kinds of midline violation, crossover and switching, may be explained by the relative position of the stem cell bandlets within the germinal bands, and by the geometrical features of the formation of the germinal plate from the germinal bands.