Qiao J, Cohen D, Herzlinger D
Department of Physiology and Biophysics, Cornell University Medical College, New York, NY 10021, USA.
Development. 1995 Oct;121(10):3207-14. doi: 10.1242/dev.121.10.3207.
The kidney forms from two tissue populations derived from intermediate mesoderm, the ureteric bud and metanephric mesenchyme. It is currently accepted that metanephric mesenchyme is committed to differentiating into nephrons while the ureteric bud is restricted to forming the renal collecting system. To test this hypothesis, we transferred lacZ into pure metanephric mesenchyme isolated from gestation day 13 rat embryos. The fate of tagged mesenchymal cells and their progeny was characterized after co-culture with isolated ureteric buds. When induced to differentiate by the native inducer of kidney morphogenesis, lineage-tagged mesenchymal cells exhibit the potential to differentiate into collecting system epithelia, in addition to nephrons. The fate of cells deriving from isolated ureteric buds was also examined and results of these lacZ gene transfer experiments indicate that the majority of ureteric bud cells differentiate into the renal collecting system. These cell fate studies combined with in situ morphological observations raise the possibility that collecting system morphogenesis in vivo occurs by growth of the ureteric bud and recruitment of mesenchymal cells from the metanephric blastema. Thus, metanephric mesenchyme may be a pluripotent renal stem population.
肾脏由源自中间中胚层的两个组织群体形成，即输尿管芽和后肾间充质。目前公认，后肾间充质致力于分化为肾单位，而输尿管芽则局限于形成肾集合系统。为了验证这一假说，我们将lacZ导入从妊娠第13天大鼠胚胎分离出的纯后肾间充质中。在与分离出的输尿管芽共培养后，对标记的间充质细胞及其后代的命运进行了表征。当由肾脏形态发生的天然诱导剂诱导分化时，谱系标记的间充质细胞除了分化为肾单位外，还表现出分化为集合系统上皮的潜力。我们还研究了源自分离出的输尿管芽的细胞的命运，这些lacZ基因转移实验的结果表明，大多数输尿管芽细胞分化为肾集合系统。这些细胞命运研究与原位形态学观察相结合，提出了一种可能性，即体内集合系统形态发生是通过输尿管芽的生长和从后肾胚基募集间充质细胞而发生的。因此，后肾间充质可能是一种多能肾干细胞群体。
