Carlson M R, Bryant S V, Gardiner D M
Developmental Biology Center, University of California, Irvine 92697-2275, USA.
J Exp Zool. 1998 Dec 15;282(6):715-23. doi: 10.1002/(sici)1097-010x(19981215)282:6<715::aid-jez7>3.0.co;2-f.
Msx genes are transcription factors that are expressed during embryogenesis of developing appendages in regions of epithelial-mesenchymal interactions. Various lines of evidence indicate that these genes function to maintain embryonic tissues in an undifferentiated, proliferative state. We have identified the axolotl homolog of Msx-2, and investigated its expression during limb development, limb regeneration, and wound healing. As in limb buds of higher vertebrates, axolotl Msx-2 is expressed in the apical epidermis and mesenchyme; however, its expression domain is more extensive, reflecting the broader region of the apical epidermal cap in amphibians. Msx-2 expression is downregulated at late stages of limb development, but is reexpressed within one hour after limb amputation. Msx-2 is also reexpressed during wound healing, and may be essential in the early stages of initiation of the limb regeneration cascade.
Msx基因是转录因子，在发育中附肢的胚胎发生过程中，于上皮-间充质相互作用区域表达。各种证据表明，这些基因的功能是使胚胎组织维持在未分化的增殖状态。我们已鉴定出Msx-2的美西螈同源物，并研究了其在肢体发育、肢体再生和伤口愈合过程中的表达情况。与高等脊椎动物的肢芽一样，美西螈Msx-2在顶端表皮和间充质中表达；然而，其表达域更广泛，这反映了两栖动物中顶端表皮帽的更广泛区域。Msx-2在肢体发育后期表达下调，但在肢体截肢后一小时内重新表达。Msx-2在伤口愈合过程中也重新表达，并且可能在肢体再生级联反应启动的早期阶段至关重要。
