Poole T J
Department of Anatomy and Cell Biology, SUNY Health Science Center, Syracuse 13210.
Scanning Microsc. 1988 Mar;2(1):411-5.
The morphology of the directed migration of the pronephric duct rudiment of three vertebrates, the salamander, chick and sturgeon, has been examined by scanning electron microscopy. Of particular interest in this paper are the morphology of the duct tip, the role of cell rearrangement, and the relation of duct extension to somite segmentation. The duct rudiments of all three species have motile cell processes (lamellipodia and filopodia) largely confined to their posterior tips. The salamander and sturgeon embryos extend their duct rudiments by extensive cell rearrangements. A short, wide rudiment is elongated to form a long, thin one. The chick duct rudiment stays about the same width and apparently gains volume by cell proliferation. The salamander duct rudiment's posterior tip is always two somites behind the last formed somite. Both the sturgeon and chick embryo's duct rudiments lie well posterior of the last segmented somite adjacent to segmental plate mesoderm. There is still a close coupling, however, between the posterior progression of the duct rudiments and the advancing wave of somite segmentation.
通过扫描电子显微镜检查了三种脊椎动物（蝾螈、鸡和鲟鱼）原肾管雏形的定向迁移形态。本文特别感兴趣的是管尖的形态、细胞重排的作用以及管延伸与体节分割的关系。所有这三个物种的管雏形都有活动的细胞突起（片状伪足和丝状伪足），主要局限于其后端。蝾螈和鲟鱼胚胎通过广泛的细胞重排来延伸它们的管雏形。一个短而宽的雏形被拉长形成一个长而细的雏形。鸡的管雏形宽度大致保持不变，显然是通过细胞增殖来增加体积。蝾螈管雏形的后端总是位于最后形成的体节后面两个体节处。鲟鱼和鸡胚胎的管雏形都位于与体节板中胚层相邻的最后分割体节的后方。然而，管雏形的后移与体节分割的推进波之间仍然存在密切的耦合。
