A Genome-Wide RNAi Screen for Factors Involved in Neuronal Specification in Caenorhabditis elegans.
A Genome-Wide RNAi Screen for Factors Involved in Neuronal Specification in Caenorhabditis elegans.
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DOI：
10.1371/journal.pgen.1002109
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发表时间：
2011-06
期刊：
影响因子：
4.5
通讯作者：
Hobert O
中科院分区：
文献类型：
--
作者：
Poole RJ;Bashllari E;Cochella L;Flowers EB;Hobert O
发育神经生物学的核心目标之一是描述和理解控制受精卵发育为终末分化神经元的多层次分子事件。在线虫秀丽隐杆线虫中，从卵到终末分化的神经元的进展已经通过谱系分析直观地追踪。例如，两个味觉神经元ASEL和ASER，一个功能上偏侧的双侧对称神经元对，是通过11个细胞分裂的不变序列从受精卵产生的，这些细胞分裂典型地沿着特定的分裂平面发生。沿着这条发育途径发生的分子事件只是表面上的了解。我们在这里采取一个公正的，全基因组的方法来确定基因，可能会在任何阶段，以确保正确的分化ASEL。通过筛选敲低18，179个基因（占基因组的94%）的全基因组RNAi文库，我们确定了245个影响ASEL神经元发育的基因，这些基因要么不产生神经元，要么将其命运转换为另一个细胞的命运，要么来自其他谱系分支的细胞现在采用ASEL命运。我们详细分析了从该屏幕中识别的两个因素：（1）前神经基因hlh-14，我们发现其在ASEL/R谱系中双侧表达，尽管它们的谱系起源不对称，并且我们发现其是从包括ASE神经元的几个谱系分支产生神经元所必需的，和（2）COMPASS组蛋白甲基转移酶复合物，我们发现它是ASEL/R不对称性的关键胚胎诱导物，作用于先前鉴定的miRNA lsy-6的上游。我们的研究代表了对单个神经元细胞命运决定的第一次全面的全基因组分析。这项分析的结果为未来的研究提供了一个起点，最终将导致更完整地了解单个神经元细胞类型是如何从单细胞胚胎中产生的。从受精卵中产生神经元需要细胞内外分子的多步级联反应，将其引向神经元的命运，而不是肌肉细胞。这些级联尚未得到充分理解。在这项研究中，我们系统地消除了C. elegans基因组，一个接一个，以确定需要什么来建立一个神经元。我们确定了245个影响特定感觉神经元对发育的基因，例如，神经元没有产生，或者神经元产生了，但没有正确指定终末命运。我们更详细地描述了转录因子hLH-14，我们发现这是需要产生多个神经元，和COMPASS组蛋白甲基转移酶复合物，我们发现有一个令人惊讶的具体作用，在这个感觉神经元对的分子和功能的左右不对称的规格。我们的研究代表了对单个神经元细胞命运决定的第一个全基因组分析。对这里确定的基因的进一步表征将增强我们对人类神经系统疾病的理解，从而提高我们治疗和预防人类神经系统疾病的能力。
One of the central goals of developmental neurobiology is to describe and understand the multi-tiered molecular events that control the progression of a fertilized egg to a terminally differentiated neuron. In the nematode Caenorhabditis elegans, the progression from egg to terminally differentiated neuron has been visually traced by lineage analysis. For example, the two gustatory neurons ASEL and ASER, a bilaterally symmetric neuron pair that is functionally lateralized, are generated from a fertilized egg through an invariant sequence of 11 cellular cleavages that occur stereotypically along specific cleavage planes. Molecular events that occur along this developmental pathway are only superficially understood. We take here an unbiased, genome-wide approach to identify genes that may act at any stage to ensure the correct differentiation of ASEL. Screening a genome-wide RNAi library that knocks-down 18,179 genes (94% of the genome), we identified 245 genes that affect the development of the ASEL neuron, such that the neuron is either not generated, its fate is converted to that of another cell, or cells from other lineage branches now adopt ASEL fate. We analyze in detail two factors that we identify from this screen: (1) the proneural gene hlh-14, which we find to be bilaterally expressed in the ASEL/R lineages despite their asymmetric lineage origins and which we find is required to generate neurons from several lineage branches including the ASE neurons, and (2) the COMPASS histone methyltransferase complex, which we find to be a critical embryonic inducer of ASEL/R asymmetry, acting upstream of the previously identified miRNA lsy-6. Our study represents the first comprehensive, genome-wide analysis of a single neuronal cell fate decision. The results of this analysis provide a starting point for future studies that will eventually lead to a more complete understanding of how individual neuronal cell types are generated from a single-cell embryo. The generation of a neuron from a fertilized egg requires a multi-step cascade of molecules acting from within and outside that cell to direct it towards a neuronal fate, rather than, say, a muscle cell. These cascades are not fully understood. In this study we systematically eliminate the function of almost all genes in the C. elegans genome, one by one, to determine what it takes to build a neuron. We identified 245 genes that affect the development of a specific sensory neuron pair, e.g. the neurons were not generated or the neurons were generated but the terminal fate was not correctly specified. We characterize in more detail the transcription factor hlh-14, which we find is required to generate multiple neurons, and the COMPASS histone methyltransferase complex, which we find to have a surprisingly specific role in the specification of a molecular and functional left-right asymmetry in this sensory neuron pair. Our study represents the first genome-wide analysis of a single neuronal cell fate decision. Further characterization of the genes identified here will enhance our understanding, and thus our capacity for treatment and prevention, of human neurological disorders.
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影响因子：
11.8
作者：
Bertrand, Vincent;Hobert, Oliver
通讯作者：
Hobert, Oliver
DOI：
10.1895/wormbook.1.12.2
发表时间：
2010-10-04
期刊：
WormBook : the online review of C. elegans biology
影响因子：
--
作者：
Hobert, Oliver
通讯作者：
Hobert, Oliver
影响因子：
64.8
作者：
Johnston, RJ;Hobert, O
通讯作者：
Hobert, O
影响因子：
4.8
作者：
Kamath, RS;Ahringer, J
通讯作者：
Ahringer, J
影响因子：
64.8
作者：
Kamath, RS;Fraser, AG;Ahringer, J
通讯作者：
Ahringer, J