Characterization of Brachyury-downstream notochord genes in the Ciona intestinalis embryo
Characterization of Brachyury-downstream notochord genes in the Ciona intestinalis embryo
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DOI：
10.1006/dbio.2000.9765
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发表时间：
2000-08-01
影响因子：
2.7
通讯作者：
Satoh, N
中科院分区：
文献类型：
--
作者：
Hotta, K;Takahashi, H;Satoh, N
脊索在脊索动物胚胎发生过程中有两个主要作用，一是作为神经管和近轴中胚层形成的诱导信号来源，二是作为幼虫尾部的支持器官。尽管最近发现了影响脊椎动物胚胎脊索发育的突变，但对分化中脊索本身表达的基因知之甚少。在尾索动物海鞘中，短尾畸形（Ci-Bra）在脊索分化中起着关键作用。在先前的研究中，我们分离了近40个在脊索细胞中表达的潜在Ci-Bra靶基因的cDNA克隆（H。Takahashi等人，1999，Genes Dev. 13，1519-1523）。在这里，我们通过确定cDNA的完整核苷酸序列来表征其中的20个。这些基因编码与脊索形成和功能相关的广谱不同蛋白质。两个基因编码果蝇刺LIM结构域蛋白的海鞘同源物，另一个编码ERM蛋白，所有3个基因似乎都参与细胞骨架结构的控制。此外，还鉴定了netrin、leprecan、cdc 45、ATP：柠檬酸裂解酶、ATP硫酸化酶/APS激酶、蛋白酪氨酸磷酸酶、β 4-半乳糖基转移酶、纤维蛋白原样蛋白、趋异原肌球蛋白样蛋白和果蝇Pellino样蛋白的基因。netrin基因在脊索中表达的观察可能为海鞘脊索和脊椎动物一样是信号源提供了第一个分子证据。此外，目前的信息应被用来确定非脊索动物后口组织同源的脊索，以及基因表达的脊索细胞的脊椎动物胚胎。(C)北京大学出版社.
The notochord has two major roles during chordate embryogenesis, as a source of inductive signals for the patterning of neural tube and paraxial mesoderm and as a supportive organ of the larval tail. Despite the recent identification of mutations that affect the notochord development in vertebrate embryos, little is known about genes that are expressed in the differentiating notochord itself. In the urochordate ascidian Ciona intestinalis, Brachyury (Ci-Bra) plays a key role in notochord differentiation. In a previous study, we isolated cDNA clones for nearly 40 potential Ci-Bra target genes that are expressed in notochord cells (H. Takahashi et al., 1999, Genes Dev. 13, 1519-1523). Here we characterized 20 of them by determining the complete nucleotide sequences of the cDNAs. These genes encode a broad spectrum of divergent proteins associated with notochord formation and function. Two genes encode ascidian homologs of the Drosophila Prickle LIM domain proteins and another encodes the ERM protein, all 3 of which appear to be involved in the control of cytoskeletal architecture. In addition, genes for netrin, leprecan, cdc45, ATP:citrate lyase, ATP sulfurylase/APS kinase, protein tyrosine phosphatase, beta 4-galactosyltransferase, fibrinogen-like protein, divergent tropomyosin-like proteins, and Drosophila Pellino-like protein were identified. The observation of the netrin gene expression in the notochord may provide the first molecular evidence that the ascidian notochord is a source of signals as in vertebrates. In addition, the present information should be used to identify nonchordate deuterostome tissues homologous to the notochord as well as genes which are expressed in the notochord cells of vertebrate embryos. (C) 2000 Academic Press.