Furukubo-Tokunaga Katsuo, Adachi Yoshitsugu, Kurusu Mitsuhiko, Walldorf Uwe
Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Japan.
Fly (Austin). 2009 Oct-Dec;3(4):263-9. doi: 10.4161/fly.10385. Epub 2009 Oct 21.
The Drosophila Pax6 genes, eyeless (ey) and twin of eyeless (toy), are expressed in both eyes and the brain. Previous studies have demonstrated that ey plays important roles in axonal outgrowth and differentiation of mushroom bodies (MBs), which are centers for associative learning and memory in flies. However, the functional significance of toy in brain development is poorly understood. Here, we describe the expression patterns of TOY, and show that TOY expression partially overlaps with EY expression in the embryonic, larval and adult brains. Mutations of toy perturb brain neuromere formation in the embryonic stages, and result in severe deformation of the MB lobes in pharate adult brains. Moreover, we also analyzed toy functions by gain-of-function experiments, and show that overexpression of toy results in degeneration of MB lobes. Thus, our results demonstrate the importance of toy in embryonic brain patterning as well as in post-embryonic development of the major brain structures such as MBs.
果蝇的Pax6基因，无眼（ey）和无眼之双（toy），在眼睛和大脑中均有表达。先前的研究表明，ey在蕈形体（MBs）的轴突生长和分化中发挥重要作用，而蕈形体是果蝇联想学习和记忆的中心。然而，toy在大脑发育中的功能意义却知之甚少。在此，我们描述了TOY的表达模式，并表明TOY的表达在胚胎、幼虫和成虫大脑中与EY的表达部分重叠。toy的突变会扰乱胚胎期大脑神经节的形成，并导致准成虫大脑中MB叶严重变形。此外，我们还通过功能获得实验分析了toy的功能，并表明toy的过表达会导致MB叶退化。因此，我们的结果证明了toy在胚胎大脑模式形成以及MBs等主要脑结构的胚后发育中的重要性。
