Fox Donald T, Spradling Allan C
Department of Embryology, Howard Hughes Medical Institute, Carnegie Institution, Baltimore, MD 21218, USA.
Cell Stem Cell. 2009 Sep 4;5(3):290-7. doi: 10.1016/j.stem.2009.06.003. Epub 2009 Aug 20.
The adult Drosophila hindgut was recently reported to contain active, tissue-replenishing stem cells, like those of the midgut, but located within an anterior ring so as to comprise a single giant crypt. In contrast to this view, we observed no active stem cells and little cell turnover in adult hindgut tissue based on clonal marking and BrdU incorporation studies. Again contradicting the previous proposal, we showed that the adult hindgut is not generated by anterior stem cells during larval/pupal development. However, severe tissue damage within the hindgut elicits cell proliferation within a ring of putative quiescent stem cells at the anterior of the pylorus. Thus, the hindgut does not provide a model of tissue maintenance by constitutively active stem cells, but has great potential to illuminate mechanisms of stress-induced tissue repair.
最近有报道称,成年果蝇的后肠含有活跃的、可补充组织的干细胞,类似于中肠的干细胞,但位于前环内,从而构成一个单一的巨大隐窝。与这一观点相反,基于克隆标记和BrdU掺入研究,我们在成年后肠组织中未观察到活跃的干细胞,且细胞更新很少。同样与之前的观点相矛盾的是,我们发现成年后肠在幼虫/蛹发育过程中并非由前体细胞产生。然而,后肠内的严重组织损伤会引发幽门前部一圈假定的静止干细胞的细胞增殖。因此,后肠并不是由组成型活跃干细胞维持组织的模型,但在阐明应激诱导的组织修复机制方面具有很大潜力。