Yamashita Yukiko M, Fuller Margaret T, Jones D Leanne
Department of Development Biology, Stanford University School of Medicine, Stanford, CA 94305, USA.
J Cell Sci. 2005 Feb 15;118(Pt 4):665-72. doi: 10.1242/jcs.01680.
Stem cells are cells that, upon division, can produce new stem cells as well as daughter cells that initiate differentiation along a specific lineage. Studies using the Drosophila germline as a model system have demonstrated that signaling from the stem cell niche plays a crucial role in controlling stem cell behavior. Surrounding support cells secrete growth factors that activate signaling within adjacent stem cells to specify stem cell self-renewal and block differentiation. In addition, cell-cell adhesion between stem cells and surrounding support cells is important for holding stem cells close to self-renewal signals. Furthermore, a combination of localized signaling and autonomously acting proteins might polarize stem cells in such a way as to ensure asymmetric stem cell divisions. Recent results describing stem cell niches in other adult stem cells, including hematopoietic and neural stem cells, have demonstrated that the features characteristic of stem cell niches in Drosophila gonads might be conserved.
干细胞是一类细胞，在分裂时，既能产生新的干细胞，也能产生开始沿特定谱系分化的子细胞。以果蝇生殖系为模型系统的研究表明，干细胞微环境发出的信号在控制干细胞行为方面起着关键作用。周围的支持细胞分泌生长因子，激活相邻干细胞内的信号，以确定干细胞的自我更新并阻止分化。此外，干细胞与周围支持细胞之间的细胞间黏附对于使干细胞接近自我更新信号很重要。此外，局部信号传导和自主作用蛋白的组合可能会使干细胞极化，从而确保干细胞进行不对称分裂。最近关于其他成体干细胞（包括造血干细胞和神经干细胞）中干细胞微环境的研究结果表明，果蝇性腺中干细胞微环境的特征可能是保守的。
