Rusconi J C, Corbin V
Department of Molecular Biosciences, University of Kansas, Lawrence 66045, USA.
Mech Dev. 1998 Dec;79(1-2):39-50. doi: 10.1016/s0925-4773(98)00170-1.
The Notch pathway mediates cell fate choice in many species and developmental contexts. In the Drosophila mesoderm, phenotypic differences were observed when different components of the pathway were defective. To determine if these differences reflect variations in the signaling pathway or in the persistence of wild-type maternal products, we examined muscle precursors in embryos that lacked both maternally- and zygotically-derived gene products, called holonull embryos. Most holonull neurogenic embryos have the same number and arrangement of extra muscle precursors, but in Notch holonull embryos many additional cells also become muscle precursors. Thus Notch is active in cells where its known ligands and downstream effectors are not. These results indicate that Notch acts in two pathways to determine cell fates in mesoderm: the Delta-to-Notch-to-Suppressor of Hairless-to-Enhancer of split signaling pathway previously defined, and a second pathway that acts independently.
Notch信号通路在许多物种和发育环境中介导细胞命运的选择。在果蝇中胚层中，当该信号通路的不同组分存在缺陷时，会观察到表型差异。为了确定这些差异是反映了信号通路的变化还是野生型母体产物的持续性，我们研究了缺乏母体和合子来源基因产物的胚胎中的肌肉前体细胞，即所谓的全 null 胚胎。大多数全 null 神经源性胚胎具有相同数量和排列的额外肌肉前体细胞，但在Notch全 null 胚胎中，许多其他细胞也会成为肌肉前体细胞。因此，Notch在其已知配体和下游效应器不存在的细胞中具有活性。这些结果表明，Notch通过两条信号通路来决定中胚层细胞的命运：一条是先前定义的Delta-Notch-无翅抑制因子-分裂增强子信号通路，另一条是独立作用的信号通路。
