Adler P N, Charlton J, Jones K H, Liu J
Biology Department, University of Virginia, Charlottesville 22903-2477.
Mech Dev. 1994 May;46(2):101-7. doi: 10.1016/0925-4773(94)90079-5.
The function of the frizzled (fz) gene is essential for the development of the normal pattern of hairs on the Drosophila wing. In the absence of fz function hairs develop, but they display an abnormal polarity. Mutations in fz result in an altered subcellular location for the assembly of the F-actin filled prehair that becomes the adult cuticular hair. This observation led to the suggestion that fz and other tissue polarity genes form a regulatory pathway that controls the initiation of prehairs. We have isolated a cold-sensitive fz allele and found that the cold-sensitive period for fz in the pupal wing starts in the early pupae and ends prior to the first sign of prehair morphogenesis. This cold-sensitive mutation is due to a missense mutation in a putative transmembrane domain. Western blot analysis shows that the accumulation of the mutant protein is not cold sensitive, consistent with the supposition that it is the activity of the mutant protein that is cold sensitive. Our data argue that fz has a regulatory function in specifying where the prehair forms, but no role in the actual morphogenesis of the prehair.
卷曲（fz）基因的功能对于果蝇翅膀上正常毛发生长模式的发育至关重要。在缺乏fz功能的情况下，毛发会生长，但它们显示出异常的极性。fz基因的突变导致填充有F-肌动蛋白的前毛组装的亚细胞位置发生改变，而前毛会发育成成虫的表皮毛。这一观察结果表明，fz和其他组织极性基因形成了一个调控途径，控制前毛的起始。我们分离出了一个冷敏感的fz等位基因，发现蛹期翅膀中fz的冷敏感时期始于早期蛹期，并在出现前毛形态发生的第一个迹象之前结束。这种冷敏感突变是由一个推定的跨膜结构域中的错义突变引起的。蛋白质免疫印迹分析表明，突变蛋白的积累对温度不敏感，这与突变蛋白的活性对温度敏感的假设一致。我们的数据表明，fz在确定前毛形成位置方面具有调控功能，但在前毛的实际形态发生过程中没有作用。
