Roles of single-minded in the left-right asymmetric development of the Drosophila embryonic gut
Roles of single-minded in the left-right asymmetric development of the Drosophila embryonic gut
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DOI：
10.1016/j.mod.2006.12.001
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发表时间：
2007-03-01
影响因子：
2.6
通讯作者：
Matsuno, Kenji
中科院分区：
文献类型：
--
作者：
Maeda, Reo;Hozumi, Shunya;Matsuno, Kenji
许多动物体内器官的左右不对称是由基因决定的。脊椎动物胚胎的中线结构在LR不对称发育中具有重要作用，它既是LR不对称的信号传导中心，也是跨中线不适当的LR信号传导的屏障。然而，在无脊椎动物中，中线在LR不对称发育中的功能尚不清楚。为了阐明这些作用，我们研究了single-minded （sim）在果蝇胚胎肠道LR不对称中的作用，这是一种刻板的、不对称的方式。sim编码bHLH/PAS转录因子，这是腹侧中线结构发育所必需的。在这里，我们报道了sim在前肠和后肠原基的中线表达。在sim突变胚和过表达sim胚中，胚胎肠的手性受到影响。然而，中线来源的事件，包括Slit/Robo和EGFr信号传导，并指导中线附近组织的发育，并不影响该器官的侧边性，这表明中线本身在LR不对称中起着至关重要的作用。在sim突变体中，胚胎肛垫的中线结构发生变形。肛门垫原基中sim的错误表达诱导了LR缺陷。我们还发现，胚胎肠的不同部分在不同时间需要正常LR不对称的sim功能。我们的研究结果表明，中线结构参与了果蝇胚胎肠道的LR不对称发育。2007爱思唯尔爱尔兰有限公司版权所有。
Many animals have genetically determined left-right (LR) asymmetry of their internal organs. The midline structure of vertebrate embryos has important roles in LR asymmetric development both as the signaling center for LR asymmetry and as a barrier to inappropriate LR signaling across the midline. However, in invertebrates, the functions of the midline in LR asymmetric development are unknown. To elucidate these roles, we studied the involvement of single-minded (sim) in the LR asymmetry of the Drosophila embryonic gut, which develops in a stereotypic, asymmetric manner. sim encodes a bHLH/PAS transcription factor that is required for the development of the ventral midline structure. Here we report that sim was expressed in the midline of the foregut and hindgut primordia. The handedness of the embryonic gut was affected in sim mutant embryos and in embryos overexpressing sim. However, midline-derived events, which involve Slit/Robo and EGFr signaling and direct the development of the tissues adjacent to the midline, did not affect the laterality of this organ, suggesting a crucial role for the midline itself in LR asymmetry. In the sim mutants, the midline structures of the embryonic anal pad were deformed. The mis-expression of sim in the anal-pad primordium induced LR defects. We also found that different portions of the embryonic gut require sim functions at different times for normal LR asymmetry. Our results suggest that the midline structures are involved in the LR asymmetric development of the Drosophila embryonic gut. (c) 2007 Elsevier Ireland Ltd. All rights reserved.