Specification of the C. elegans MS blastomere by the T-box factor tbx-35
Specification of the C. elegans MS blastomere by the T-box factor tbx-35
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DOI：
10.1242/dev.02475
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发表时间：
2006-08-15
期刊：
影响因子：
4.6
通讯作者：
Maduro, Morris F.
中科院分区：
文献类型：
--
作者：
Broitman-Maduro, Gina;Lin, Katy Tan-Hui;Maduro, Morris F.
在秀丽隐杆线虫中，许多中胚层细胞类型是由祖先MS的后代在胚胎发育的七细胞阶段产生的。MS的后代对体壁肌肉和咽部后半部有贡献。我们以前已经表明，MS是由发散的med -1,2 GATA因子的活性指定的。我们报道med -1,2靶基因tbx-35编码T-box转录因子，决定MS的命运。假设的tbx-35-null突变的纯合子胚胎不能产生ms来源的咽和身体肌肉，而是产生异位pal -1依赖的肌肉和皮下组织，这些组织通常由C卵裂球产生。相反，过表达tbx-35会导致异位咽和肌肉组织的产生。MS和E姐妹细胞通过核效应物TCF/POP-1转导Wnt/MAPK/Src通路信号而不同。我们发现，在E中，tbx-35以Wnt依赖的方式被抑制，而不需要TCF/POP-1的活性，这表明在E中有一个额外的核Wnt效应物抑制MS的发展。已知T-box家族的基因在原口动物和后口动物中对中胚层命运的规范起作用。我们的研究结果表明，这种作用在早期秀丽隐杆线虫胚胎中已经进化保守，并且多种组织类型的祖细胞可以通过一个令人惊讶的简单基因级联来指定。
In C. elegans, many mesodermal cell types are made by descendants of the progenitor MS, born at the seven-cell stage of embryonic development. Descendants of MS contribute to body wall muscle and to the posterior half of the pharynx. We have previously shown that MS is specified by the activity of the divergent MED-1,2 GATA factors. We report that the MED-1,2 target gene tbx-35, which encodes a T-box transcription factor, specifies the MS fate. Embryos homozygous for a putative tbx-35-null mutation fail to generate MS-derived pharynx and body muscle, and instead generate ectopic PAL-1-dependent muscle and hypodermis, tissues normally made by the C blastomere. Conversely, overexpression of tbx-35 results in the generation of ectopic pharynx and muscle tissue. The MS and E sister cells are made different by transduction of a Wnt/MAPK/Src pathway signal through the nuclear effector TCF/POP-1. We show that in E, tbx-35 is repressed in a Wnt-dependent manner that does not require activity of TCF/POP-1, suggesting that an additional nuclear Wnt effector functions in E to repress MS development. Genes of the T-box family are known to function in protostomes and deuterostomes in the specification of mesodermal fates. Our results show that this role has been evolutionarily conserved in the early C. elegans embryo, and that a progenitor of multiple tissue types can be specified by a surprisingly simple gene cascade.