Bard J B, Gordon A, Sharp L, Sellers W I
Department of Biomedical Sciences, University of Edinburgh, UK.
J Anat. 2001 Oct;199(Pt 4):385-92. doi: 10.1046/j.1469-7580.2001.19940385.x.
This paper reports 3-dimensional confocal microscopy observations on how nephrogenic aggregates form from the NCAM- and Pax2-positive caps (4-5 cells deep) of condensed metanephric mesenchyme surrounding the duct tips of the mouse kidney. Aggregates of 6-8 cells are first seen at approximately E12.5-12.75 immediately proximal to this cap, closely abutting the duct surface. As the tip advances, NCAM expression is maintained in the cap but is otherwise restricted to aggregates whose cells rapidly epithelialise, forming tubules that invade the duct epithelium. Pax2 expression studies shows how the rind of nephrogenic blastemal cells forms: as duct tips extend towards the kidney surface, the associated Pax2+ cells form patches of cells on the kidney surface. These observations revise our knowledge of the timing and process of nephron initiation.
本文报道了利用三维共聚焦显微镜对小鼠肾脏导管末端周围凝聚的后肾间充质中NCAM和Pax2阳性帽（4 - 5个细胞深）如何形成肾源性聚集体的观察结果。在大约胚胎第12.5 - 12.75天，首先在紧邻该帽的近端观察到6 - 8个细胞的聚集体，它们紧密邻接导管表面。随着导管末端向前推进，NCAM在帽中持续表达，但在其他地方则局限于其细胞迅速上皮化的聚集体，这些聚集体形成侵入导管上皮的小管。Pax2表达研究揭示了肾源性胚基细胞外皮的形成方式：随着导管末端向肾脏表面延伸，相关的Pax2 +细胞在肾脏表面形成细胞斑块。这些观察结果修正了我们对肾单位起始时间和过程的认识。
