García-Alonso L, VanBerkum M F, Grenningloh G, Schuster C, Goodman C S
Howard Hughes Medical Institute, Department of Molecular and Cell Biology, University of California, Berkeley 94720, USA.
Proc Natl Acad Sci U S A. 1995 Nov 7;92(23):10501-5. doi: 10.1073/pnas.92.23.10501.
Fasciclin II (Fas II), an NCAM-like cell adhesion molecule in Drosophila, is expressed on a subset of embryonic axons and controls selective axon fasiculation. Fas II is also expressed in imaginal discs. Here we use genetic analysis to show that Fas II is required for the control of proneural gene expression. Clusters of cells in the eye-antennal imaginal disc express the achaete proneural gene and give rise to mechanosensory neurons; other clusters of cells express the atonal gene and give rise to ocellar photoreceptor neurons. In fasII loss-of-function mutants, the expression of both proneural genes is absent in certain locations, and, as a result, the corresponding sensory precursors fail to develop. In fasII gain-of-function conditions, extra sensory structures arise from this same region of the imaginal disc. Mutations in the Abelson tyrosine kinase gene show dominant interactions with fasII mutations, suggesting that Abl and Fas II function in a signaling pathway that controls proneural gene expression.
成束蛋白II（Fas II）是果蝇中一种与神经细胞黏附分子（NCAM）类似的细胞黏附分子，在一部分胚胎轴突上表达，并控制轴突的选择性成束。Fas II也在成虫盘表达。在此，我们通过遗传学分析表明，Fas II是控制神经前体基因表达所必需的。眼触角成虫盘中的细胞簇表达achaete神经前体基因，并产生机械感觉神经元；其他细胞簇表达无调基因，并产生单眼感光神经元。在fasII功能丧失突变体中，这两个神经前体基因在某些位置均不表达，结果相应的感觉前体细胞无法发育。在fasII功能获得的情况下，成虫盘的同一区域会产生额外的感觉结构。阿贝尔森酪氨酸激酶基因的突变与fasII突变表现出显性相互作用，表明Abl和Fas II在控制神经前体基因表达的信号通路中发挥作用。
