ANTENNAPEDIA-CLASS HOMEOBOX GENES DEFINE DIVERSE NEURONAL SETS IN THE EMBRYONIC CNS OF THE LEECH
ANTENNAPEDIA-CLASS HOMEOBOX GENES DEFINE DIVERSE NEURONAL SETS IN THE EMBRYONIC CNS OF THE LEECH
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DOI：
10.1002/neu.480241012
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发表时间：
1993-10-01
期刊：
影响因子：
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通讯作者：
MACAGNO, ER
中科院分区：
文献类型：
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作者：
AISEMBERG, GO;WYSOCKADILLER, J;MACAGNO, ER
研究表明，这些转录因子的特定组合在定义神经元的身份中发挥作用。我们研究了这些基因在水蛭水蛭medicularis，一个有机体非常适合在确定的神经元水平的神经生物学研究的表达。尽管水蛭身体结构的复杂性明显较低，但水蛭至少含有与昆虫一样多的水蛭纲和相关基因。详细研究了两个水蛭同源异型盒基因（Lox基因）的CNS表达模式。Lox 1在早期神经节发生期间仅在每个节段中存在的一对瞬时神经元（双极细胞）中表达，并且在胚胎发育的后期阶段，在大多数节段中重复的15-20对中枢神经元中表达。单克隆抗体Laz 1 -1将两对Lox 1表达神经元鉴定为双极细胞和L1神经元。双极细胞在纵连神经原基上延伸出突起，随后退化。L1神经元在神经节发生的后期被检测到，并成为稳定的神经元。Lox 2在CNS后三分之二的神经元的迭代集合中表达。根据胞体位置和相对大小，两对Lox 2表达细胞被鉴定为RPE样神经元和CV运动神经元。其他Lox基因也在神经元的分段重复亚群中表达。这些神经元亚群似乎彼此不同，但部分重叠。理论上，可能在单个细胞中表达的Lox基因的不同组合可以产生足够的变异性，以指定水蛭神经节中的所有中枢神经元。(C)John Wiley & Sons，Inc.
Studies of the Antennapedia-class homeobox genes suggest that specific combinations of these transcription factors play a role in defining neuronal identities. We examined the expression of these genes in the leech Hirudo medicinalis, an organism well-suited for neurobiological research at the level of identified neurons. Leeches contain at least as many Antennapedia-class and related genes as insects do, despite the apparently lower complexity of the leech body plan. The CNS expression patterns of two Antennapedia-class leech homeobox genes (Lox genes) were examined in detail. Lox1 is expressed during early gangliogenesis in only one pair of transient neurons present in every segment (the Bipolar cells) and, at later stages of embryonic development, in 15-20 pairs of central neurons repeated in most segments. The monoclonal antibody Laz1-1 identified two pairs of Lox1-expressing neurons as the Bipolar cells and the L1 neurons. The Bipolar cells extended processes in the primordia of the longitudinal connective nerves and later degenerated. The L1 neurons were detected late in gangliogenesis and became stable neurons. Lox2 is expressed in an iterated set of neurons in the posterior two-thirds of the CNS. On the basis of cell body position and relative size, two pairs of Lox2-expressing cells were identified as the RPE-like neurons and the CV motor neurons. Other Lox genes are also expressed in segmentally repeated subpopulations of neurons. These neuronal subpopulations appear to be different from one another but partially overlapping. Different combinations of Lox genes that may be expressed in individual cells could in theory generate enough variability to specify all central neurons in a leech ganglion. (C) 1993 John Wiley & Sons, Inc.