Brown N L, Paddock S W, Sattler C A, Cronmiller C, Thomas B J, Carroll S B
Howard Hughes Medical Institute and Bock Laboratories, Madison, Wisconsin 53706, USA.
Dev Biol. 1996 Oct 10;179(1):65-78. doi: 10.1006/dbio.1996.0241.
Initiation of Drosophila peripheral nervous system (PNS) development requires the achaete-scute complex (AS-C) and the atonal (ato) genes. The AS-C and ato encode basic helix-loop-helix (bHLH) transcription factors that dimerize in vitro with another bHLH protein, daughterless (da). da has many functions during Drosophila embryonic development, as it is required for proper sex determination, oogenesis, and neurogenesis. Here, we examine the expression and function of da within the developing Drosophila eye. The use of a monoclonal antibody to the Da protein revealed that Da levels are modulated across the developing eye disc. Within the morphogenetic furrow (MF) and photoreceptor cell R8, there is a cell-by-cell correspondence between high levels of Da protein expression and Ato protein expression. Mosaic analysis of adult tissue demonstrates that da function is cell autonomous and required within R2, R3, R4, R5, and R8. Examination of gene expression in da- imaginal disc clones reveals that da regulates Ato expression in the MF, affects the progression of the MF, and is necessary for the reestablishment of the G2 and M phases of the synchronized cell cycle posterior to the MF.
果蝇外周神经系统（PNS）发育的起始需要achaete-scute复合体（AS-C）和无调性（ato）基因。AS-C和ato编码碱性螺旋-环-螺旋（bHLH）转录因子，它们在体外能与另一种bHLH蛋白——无女儿（da）二聚化。da在果蝇胚胎发育过程中有许多功能，因为它对于正确的性别决定、卵子发生和神经发生是必需的。在这里，我们研究了da在发育中的果蝇眼睛中的表达和功能。使用针对Da蛋白的单克隆抗体显示，Da水平在发育中的眼盘中受到调节。在形态发生沟（MF）和感光细胞R8内，高水平的Da蛋白表达与Ato蛋白表达之间存在逐个细胞的对应关系。对成虫组织的镶嵌分析表明，da功能是细胞自主的，并且在R2、R3、R4、R5和R8中是必需的。对da突变的成虫盘克隆中的基因表达进行检查发现，da在MF中调节Ato表达，影响MF的进程，并且对于MF后方同步细胞周期的G2期和M期的重新建立是必需的。
