Maduro M F, Meneghini M D, Bowerman B, Broitman-Maduro G, Rothman J H
Department of Molecular, Cellular, and Developmental Biology and Neuroscience Research Institute, University of California, Santa Barbara 93106, USA.
Mol Cell. 2001 Mar;7(3):475-85. doi: 10.1016/s1097-2765(01)00195-2.
The endoderm and much of the mesoderm arise from the EMS cell in the four-cell C. elegans embryo. We report that the MED-1 and -2 GATA factors specify the entire fate of EMS, which otherwise produces two C-like mesectodermal progenitors. The meds are direct targets of the maternal SKN-1 transcription factor; however, their forced expression can direct SKN-1-independent reprogramming of non-EMS cells into mesendodermal progenitors. We find that SGG-1/GSK-3beta kinase acts both as a Wnt-dependent activator of endoderm in EMS and an apparently Wnt-independent repressor of the meds in the C lineage, indicating a dual role for this kinase in mesendoderm development. Our results suggest that a broad tissue territory, mesendoderm, in vertebrates has been confined to a single cell in nematodes through a common gene regulatory network.
内胚层和大部分中胚层起源于秀丽隐杆线虫四细胞胚胎中的EMS细胞。我们报告称，MED-1和MED-2 GATA因子决定了EMS的全部命运，否则EMS会产生两个C样中胚层外胚层祖细胞。meds是母体SKN-1转录因子的直接靶标；然而，它们的强制表达可将非EMS细胞独立于SKN-1重编程为中内胚层祖细胞。我们发现SGG-1/GSK-3β激酶既是EMS中内胚层的Wnt依赖性激活剂，又是C系中meds的明显Wnt非依赖性抑制剂，表明该激酶在中内胚层发育中具有双重作用。我们的结果表明，脊椎动物中一个广泛的组织区域——中内胚层，通过一个共同的基因调控网络，在秀丽隐杆线虫中被限制在单个细胞中。
