The LIM homeodomain protein dLim1 defines a subclass of neurons within the embryonic ventral nerve cord of Drosophila
The LIM homeodomain protein dLim1 defines a subclass of neurons within the embryonic ventral nerve cord of Drosophila
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DOI：
10.1016/s0925-4773(99)00189-6
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发表时间：
1999-11-01
影响因子：
2.6
通讯作者：
Botas, J
中科院分区：
文献类型：
--
作者：
Lilly, B;O'Keefe, DD;Botas, J
转录因子的LIM同源结构域家族的成员已经涉及在一系列物种中指定细胞身份。在果蝇中，三个LIM同源盒基因，apterous，lim 3和isl，已被证明控制胚胎内神经元子集的轴突寻路。在这里，我们描述了另一个LIM同源框基因在果蝇称为dlim 1，同源的脊椎动物Lim-1基因的分离和表征。dLim 1的序列和表达与其脊椎动物同源物高度相关。在果蝇胚胎中，dLim 1表达于头原基、脑叶以及腹神经索内不同的运动神经元和中间神经元。相比之下，在脊椎动物中，Lim-1（Lhx 1）沿着与Lim-3（Lhx 3）、Gsh-4（Lhx 4）、Isl-1和Isl-2一起在发育中的运动神经元中沿脊柱沿着表达，其中它们的重叠表达表明这些基因在建立特定运动神经元亚型中的作用。dLim 1在所有表达Isl、Lim 3和Apterous的细胞中都不存在，表明这些蛋白质在果蝇胚胎中独立发挥作用。为了研究dlim 1的功能，我们在该基因座内产生了功能缺失突变。我们的研究结果表明，dlim 1是一个必要的基因，当突变的结果在幼虫蛹边界附近的致死性。与脊椎动物的Lim-1不同，dlim 1在果蝇胚胎的前部模式中没有明显的作用。我们的分析表明，dlim 1已进化保守，但果蝇lim 1基因表现出独特的性能，区分它与脊椎动物同源物。(C)1999爱思唯尔科学爱尔兰有限公司保留所有权利。
Members of the LIM homeodomain family of transcription factors have been implicated in specifying cell identity in a range of species. In Drosophila three LIM homeobox genes, apterous, lim3 and isl, have been shown to control axon pathfinding of subsets of neurons within the embryo. Here we describe the isolation and characterization of another LIM homeobox gene in Drosophila termed dlim1, a homolog of the vertebrate Lim-1 gene. The sequence and expression of dLim1 is highly related to its vertebrate homologs. Within the Drosophila embryo, dLim1 is expressed in the head primordia, the brain lobes, and in distinct sets of motorneurons and interneurons within the ventral nerve cord. Comparatively in vertebrates, Lim-1 (Lhx1) along with Lim-3 (Lhx3), Gsh-4 (Lhx4), Isl-1 and Isl-2 are expressed in developing motorneurons along the spinal column, where their overlapping expression suggests a role for these genes in the establishment of specific motorneuron subtypes. dLim1 is absent from all cells expressing Isl, Lim3, and Apterous, indicating that these proteins function independently within the Drosophila embryo. To investigate the function of dlim1, we generated loss-of-function mutations within the locus. Our findings show that dlim1 is an essential gene that when mutated results in lethality near the larval-pupal boundary. In contrast to vertebrate Lim-1, dlim1 has no apparent role in anterior patterning of the Drosophila embryo. Our analysis shows that dlim1 has been evolutionarily conserved, however the Drosophila lim1 gene exhibits unique properties that distinguishes it from its vertebrate homologs. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.