Ashraf Shovon I, Ganguly Atish, Roote John, Ip Y Tony
Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA.
Dev Dyn. 2004 Oct;231(2):379-86. doi: 10.1002/dvdy.20130.
The Snail family of zinc-finger transcriptional repressors is essential for morphogenetic cell movements, mesoderm formation, and neurogenesis during embryonic development. These proteins also control cell cycle, cell death, and cancer progression. In Drosophila, three members of this protein family, Snail, Escargot, and Worniu, have essential but redundant functions in asymmetric cell division of neuroblasts. In addition, Snail is critical for early mesoderm formation and Escargot is required for maintaining diploidy in wing imaginal disc cells. In this report, we demonstrate that Worniu plays a role in brain development. We show that alleles of the l(2)35Da complementation group are mutants of worniu. The developing larvae of these mutant alleles fail to shorten their brainstems. The brain phenotype, as well as the lethality, of these mutants can be rescued by worniu transgenes. Moreover, RNAi experiments targeting the worniu transcript show the same nonshortening phenotype in larval brains. worniu is expressed in the neuroblasts of brain hemispheres and ventral ganglions. The results suggest that the loss of Worniu function within the neuroblasts ultimately causes the larval brainstem to fail to go through shortening during development.
锌指转录抑制因子的Snail家族对于胚胎发育过程中的形态发生细胞运动、中胚层形成和神经发生至关重要。这些蛋白质还控制细胞周期、细胞死亡和癌症进展。在果蝇中，该蛋白质家族的三个成员Snail、Escargot和Worniu在神经母细胞的不对称细胞分裂中具有重要但冗余的功能。此外，Snail对早期中胚层形成至关重要，而Escargot是维持翅成虫盘细胞二倍体所必需的。在本报告中，我们证明Worniu在脑发育中起作用。我们表明l(2)35Da互补群的等位基因是worniu的突变体。这些突变等位基因的发育幼虫未能缩短其脑干。这些突变体的脑表型以及致死性可以通过worniu转基因挽救。此外，针对worniu转录本的RNAi实验在幼虫脑中显示出相同的非缩短表型。worniu在脑半球和腹神经节的神经母细胞中表达。结果表明，神经母细胞内Worniu功能的丧失最终导致幼虫脑干在发育过程中无法缩短。
