Vize P D, Jones E A, Pfister R
Department of Zoology, University of Texas at Austin 78712, USA.
Dev Biol. 1995 Oct;171(2):531-40. doi: 10.1006/dbio.1995.1302.
The pronephros serves as the embryonic kidney of the lower vertebrates. In this report we describe the development of the pronephric system of Xenopus laevis utilizing scanning electron microscopy and novel monoclonal antibodies that specifically recognize different parts of the pronephros. Antibody 3G8 recognizes the tubules and nephrostomes of the pronephroi only and does not react with the duct. Antibody 4A6 stains only the duct and the nephrostomes. These antibodies thus allow the positive identification of these two intermediate mesoderm derivatives. Both reagents detect antigens expressed some time after the pronephric structures first form and probably represent markers of terminal differentiation. When the tubules and duct first form they are separate structures that can easily be distinguished; the connective tubules have a distinctive organization, the collecting (or common) tubule is broader than other tubules, and the narrow pronephric duct has a specific shape and position. In later stages the collecting tubule and the rostral portion of the duct undergo a considerable amount of convolution, and both contribute to the final coiled tubular body of the pronephros. The ability of 3G8 and 4A6 to distinguish these two elements of the nephric system was used to reexplore classical experiments on the interaction between these two structures during development of the pronephric system. The use of whole-mount analysis has allowed us to examine large numbers of embryos from different stages and dissected in a variety of planes. These experiments demonstrate the dynamic nature of the intermediate mesoderm and indicate that although the pronephros may be specified by mid-neurula stages, patterning is not complete until tailbud stages.
前肾是低等脊椎动物的胚胎肾。在本报告中，我们利用扫描电子显微镜和特异性识别前肾不同部位的新型单克隆抗体，描述了非洲爪蟾前肾系统的发育过程。抗体3G8仅识别前肾的肾小管和肾口，与导管不发生反应。抗体4A6仅对导管和肾口进行染色。因此，这些抗体能够对这两种中胚层衍生物进行阳性鉴定。两种试剂检测到的抗原在前肾结构首次形成后的一段时间表达，可能代表终末分化的标志物。当肾小管和导管首次形成时，它们是易于区分的独立结构；连接小管具有独特的组织结构，集合（或共同）小管比其他小管更宽，狭窄的前肾导管具有特定的形状和位置。在后期，集合小管和导管的头端部分会经历大量的卷曲，二者共同构成了前肾最终的盘曲管状结构。利用3G8和4A6区分肾系统这两个组成部分的能力，我们重新探讨了关于前肾系统发育过程中这两个结构之间相互作用的经典实验。整装分析的方法使我们能够检查来自不同阶段、在各种平面上解剖的大量胚胎。这些实验证明了中胚层的动态性质，并表明尽管前肾可能在神经胚中期阶段就已确定，但直到尾芽期模式形成才完成。
