Kaufmann Lilian T, Gierl Mathias S, Niehrs Christof
Division of Molecular Embryology, DKFZ-ZMBH Alliance, Deutsches Krebsforschungszentrum, Im Neuenheimer Feld 581, D-69120 Heidelberg, Germany.
Gene Expr Patterns. 2011 Dec;11(8):465-70. doi: 10.1016/j.gep.2011.07.005. Epub 2011 Aug 6.
Gadd45 proteins have been implicated in the cellular response to physiological or environmental stress and the accompanying cell cycle arrest, DNA repair, cell survival and senescence or apoptosis. Although their molecular function is well studied, the expression and role of Gadd45 genes during embryonic development in mice is largely unknown. Here we provide a comprehensive comparison of Gadd45a, Gadd45b and Gadd45g expression during mouse embryonic development. In situ hybridizations on sectioned and whole mouse embryos show most prominent Gadd45a expression in the tip of the closing neural tube, the cranial and dorsal root ganglia and the somites. Mouse Gadd45b is expressed strongly in the chorion, but only weakly in the embryo proper, including somites and limb buds. Murine Gadd45g expression strongly resembles Xenopus and medaka fish expression in primary neuron precursors and post-mitotic neurons, indicating a conserved role for Gadd45g in vertebrate neurogenesis. Additionally, Gadd45 genes show conserved expression during somitogenesis. In summary, Gadd45 genes are expressed in evolutionary conserved, but also divergent domains, which predominantly encompass areas of cell differentiation, consistent with their established function in growth arrest and DNA demethylation.
Gadd45蛋白与细胞对生理或环境应激的反应以及随之而来的细胞周期停滞、DNA修复、细胞存活和衰老或凋亡有关。尽管对其分子功能已有深入研究，但Gadd45基因在小鼠胚胎发育过程中的表达和作用仍 largely未知。在此，我们全面比较了Gadd45a、Gadd45b和Gadd45g在小鼠胚胎发育过程中的表达情况。对切片和完整小鼠胚胎进行的原位杂交显示，Gadd45a在闭合神经管的顶端、颅神经节和背根神经节以及体节中表达最为显著。小鼠Gadd45b在绒毛膜中强烈表达，但在胚胎本身，包括体节和肢芽中表达较弱。小鼠Gadd45g的表达与非洲爪蟾和青鳉鱼在初级神经元前体和有丝分裂后神经元中的表达非常相似，表明Gadd45g在脊椎动物神经发生中具有保守作用。此外，Gadd45基因在体节发生过程中表现出保守的表达。总之，Gadd45基因在进化上保守但也有差异的区域表达，这些区域主要包括细胞分化区域，这与其在生长停滞和DNA去甲基化方面已确立的功能一致。
