Coelho C N, Upholt W B, Kosher R A
Department of Anatomy, School of Medicine, University of Connecticut Health Center, Farmington 06030.
Dev Biol. 1993 Mar;156(1):303-6. doi: 10.1006/dbio.1993.1078.
The apical ectodermal ridge expresses high amounts of the homeobox gene GHox-8 when placed upon dissociated limb mesenchymal cells in culture and induces high expression of GHox-7, but only low expression of GHox-8, in the underlying mesenchymal cells. Ectoderm from the proximal anterior border of the limb induces high expression of both GHox-7 and GHox-8, while ectoderm from the proximal posterior border does not induce expression of either gene. Thus, ectoderm in various regions of the limb bud has distinct regulatory activities and may be involved in controlling the regionally specific expression of GHox-7 and GHox-8 in the mesoderm.
当置于解离的肢体间充质细胞上进行培养时，顶端外胚层嵴会大量表达同源框基因GHox - 8，并诱导其下方间充质细胞中GHox - 7的高表达，但仅诱导GHox - 8的低表达。来自肢体近端前缘的外胚层可诱导GHox - 7和GHox - 8的高表达，而来自近端后缘的外胚层则不诱导这两种基因的表达。因此，肢体芽不同区域的外胚层具有不同的调节活性，可能参与控制中胚层中GHox - 7和GHox - 8的区域特异性表达。
