Henry G L, Melton D A
Howard Hughes Medical Institute, Department of Molecular and Cellular Biology, Harvard University, 7 Divinity Avenue, Cambridge, MA 02138, USA.
Science. 1998 Jul 3;281(5373):91-6. doi: 10.1126/science.281.5373.91.
An expression cloning strategy in Xenopus laevis was used to isolate a homeobox-containing gene, Mixer, that can cause embryonic cells to form endoderm. Mixer transcripts are found specifically in the prospective endoderm of gastrula, which coincides with the time and place that endodermal cells become histologically distinct and irreversibly determined. Loss-of-function studies with a dominant inhibitory mutant demonstrate that Mixer activity is required for endoderm development. In particular, the expression of Sox17alpha and Sox17beta, two previously identified endodermal determinants, require Mixer function. Together, these data suggest that Mixer is an embryonic transcription factor involved in specifying the endodermal germ layer.
在非洲爪蟾中采用表达克隆策略分离出一个含同源异型框的基因Mixer，该基因可使胚胎细胞形成内胚层。Mixer转录本特异性地出现在原肠胚的预定内胚层中，这与内胚层细胞在组织学上变得不同且不可逆地确定的时间和位置一致。利用显性抑制突变体进行的功能丧失研究表明，内胚层发育需要Mixer活性。特别是，两个先前确定的内胚层决定因子Sox17α和Sox17β的表达需要Mixer功能。这些数据共同表明，Mixer是一种参与确定内胚层胚层的胚胎转录因子。
