Blair S S, Weisblat D A
Dev Biol. 1984 Feb;101(2):318-25. doi: 10.1016/0012-1606(84)90145-3.
In embryonic development of the leech Helobdella triserialis, each of the four paired ectodermal teloblasts contributes some progeny to a characteristic dorsal or ventral territory of the epidermis. To ascertain the relative roles of cell lineage and cell interactions in generating the highly regular epidermal distribution pattern of the various ectodermal cell lines, a series of experiments was carried out in which the ablation of particular teloblasts was combined with the intracellular injection of cell lineage tracers. The results showed that, after the ablation of an OP proteloblast, or of an O, P, or Q teloblast, the epidermal progeny of the remaining ipsilateral and contralateral teloblasts spread into the territory normally occupied by the epidermal progeny of the ablated teloblast. In this spreading process, cells may cross the ventral midline but not the dorsal midline. The spread of epidermal progeny of one teloblast in response to ablation of another teloblast is contrasted with the failure of the neuronal progeny of one teloblast to replace any missing neural tissue. It appears, therefore, that all epidermal cell lines are of equal developmental potential, regardless of their teloblast of origin, with the eventual location of any epidermal cell in the body wall being governed by interactions between cells within the developing epidermis.
在三带水蛭（Helobdella triserialis）的胚胎发育过程中，四对表皮端细胞中的每一对都会为表皮的特定背侧或腹侧区域贡献一些后代细胞。为了确定细胞谱系和细胞间相互作用在生成各种表皮细胞系高度规则的表皮分布模式中的相对作用，进行了一系列实验，其中将特定端细胞的切除与细胞谱系示踪剂的细胞内注射相结合。结果表明，在切除一个OP原端细胞，或一个O、P或Q端细胞后，其余同侧和对侧端细胞的表皮后代会扩散到通常由被切除端细胞的表皮后代占据的区域。在这个扩散过程中，细胞可以穿过腹中线，但不能穿过背中线。一个端细胞的表皮后代因另一个端细胞被切除而发生的扩散，与一个端细胞的神经元后代无法替代任何缺失的神经组织形成对比。因此，似乎所有表皮细胞系都具有相等的发育潜能，无论它们起源于哪个端细胞，体壁中任何表皮细胞的最终位置都由发育中的表皮内细胞间的相互作用决定。
