Daga A, Karlovich C A, Dumstrei K, Banerjee U
Department of Molecular, Cell and Developmental Biology, Molecular Biology Institute, Los Angeles.
Genes Dev. 1996 May 15;10(10):1194-205. doi: 10.1101/gad.10.10.1194.
The lozenge (lz) gene encodes a transcription factor involved in prepatterning photoreceptor precursors in the developing Drosophila eye. The central region of the predicted Lz protein product is homologous to AML1, a transcription factor associated with human leukemias, and to the Drosophila protein Runt. We show here that Lz plays a crucial role in governing the fate of two groups of cells that are born in a single round of mitosis in the larval eye disc. Lz helps define a subset of these cells as an equipotential group that is competent to respond to the Sevenless developmental signal. This is achieved by negative regulation of seven-up, a member of the steroid hormone receptor superfamily in these cells. In contrast, in a second group of cells, the Lz protein confers proper photoreceptor identity by positively regulating the homeo box gene Bar. Additionally, our genetic analysis suggests that Lz interacts with the Ras pathway to determine photoreceptor cell fate. This study suggests that the strategies involved in cell fate determination in the Drosophila eye are remarkably similar to those utilized during vertebrate hematopoietic development and require the coordinate action of growth factor and AML1-like pathways.
菱形（lz）基因编码一种转录因子，该转录因子参与果蝇发育中的眼睛中光感受器前体的预模式形成。预测的Lz蛋白产物的中央区域与AML1同源，AML1是一种与人类白血病相关的转录因子，也与果蝇蛋白Runt同源。我们在此表明，Lz在控制幼虫眼盘中一轮有丝分裂产生的两组细胞的命运中起关键作用。Lz有助于将这些细胞的一个子集定义为一个等潜能组，该组有能力对Sevenless发育信号作出反应。这是通过对这些细胞中类固醇激素受体超家族成员seven-up的负调控来实现的。相反，在第二组细胞中，Lz蛋白通过正向调控同源框基因Bar赋予适当的光感受器身份。此外，我们的遗传分析表明，Lz与Ras途径相互作用以确定光感受器细胞的命运。这项研究表明，果蝇眼睛中细胞命运决定所涉及的策略与脊椎动物造血发育过程中所使用的策略非常相似，并且需要生长因子和AML1样途径的协同作用。
