Twist protein in mouse embryogenesis
Twist protein in mouse embryogenesis
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DOI：
10.1006/dbio.1997.8614
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发表时间：
1997-09-15
影响因子：
2.7
通讯作者：
Gitelman, I
中科院分区：
文献类型：
--
作者：
Gitelman, I
bHLH转录因子twist家族中的基因对于脊椎动物和无脊椎动物的胚胎发生都是必需的，如果蝇和小鼠twist无效突变体的胚胎致死表型所证明的。本文介绍了小鼠Twist蛋白（MTwist）的胚胎分布。它的外观和存在的过程中的早期胚胎发生后，与单克隆抗体，α TwiMab-1，第一个抗体产生的任何脊椎动物扭曲蛋白。在比较Western印迹实验、网织红细胞裂解物测定和胚胎小鼠样品的免疫组织化学中证明了MTwist的特异性。与其作为转录因子的可能作用一致，MTwist定位于细胞核。MTwist信号首先出现在8- 10体节胚胎的8.25 dpc的颅神经嵴细胞和鳃弓，在肢芽间充质和体侧板，并在硬结和皮节的体节。这些组织中MTwist蛋白的存在证实了所报道的MTwist RNA分布和MTwist无效突变体的表型。然而，MTwist RNA和蛋白质表达之间也出现了意想不到的差异。在8.25 dpc之前不能检测到蛋白质，尽管早在7.0 dpc就报道了高水平的转录本。此外，前体节中胚层，上皮体节，和前中胚层表达丰富的MTwist RNA，但没有蛋白质。结果表明，转录后下调MTwist在这些地区。MTwist在体节形成和成熟中的作用是抑制肌原性bHLH和MEF 2基因，从而防止体节前中胚层和上皮体节中的过早和/或异位分化。MTwist蛋白从这些地区的情况下，表明它在体节发生的作用必须重新评估。(C)北京：科学出版社.
The genes in the twist family of bHLH transcription factors are essential for embryogenesis of both vertebrates and invertebrates, as demonstrated by the embryonic lethal phenotypes of the Drosophila and mouse twist-null mutants. Presented here is the embryonic distribution of murine Twist protein (MTwist). Its appearance and presence in the course of early embryogenesis was followed with a monoclonal antibody, alpha TwiMab-1, the first antibody generated against any of the vertebrate Twist proteins. The specificity for MTwist was demonstrated in comparative Western blot experiments, reticulocyte lysate assays, and immunohistochemistry of embryonic mouse samples. Consistent with its probable role as a transcription factor, MTwist localized to the nuclei. MTwist signal first appeared in 8- to 10-somite embryos at 8.25 dpc in the cranial neural crest cells and branchial arches, in the limb-bud mesenchyme and the somatic lateral plate, and in the sclerotome and the dermatome of the somites. The presence of MTwist protein in these tissues corroborates the reported MTwist RNA distribution and the phenotype of the MTwist-null mutants. There also emerged, however, an unexpected difference between MTwist RNA and protein expression. No protein could be detected prior to 8.25 dpc, despite the reported high levels of transcripts as early as 7.0 dpc. Also, the presomitic mesoderm, epithelial somites, and anterior mesoderm expressed abundant MTwist RNA, but no protein. The results suggest posttranscriptional downregulation of MTwist in these regions. A proposed role of MTwist in somite formation and maturation is inhibition of myogenic bHLH and MEF2 genes and thus prevention of premature and/or ectopic differentiation in the presomitic mesoderm and epithelial somites. The absence of MTwist protein from these areas indicates that its role in somitogenesis must be reevaluated. (C) 1997 Academic Press.