Tavares A T, Izpisúja-Belmonte J C, Rodriguez-León J
Instituto Gulbenkian de Ciência, Oeiras, Portugal.
Int J Dev Biol. 2001 Sep;45(5-6):707-13.
We have isolated a chick Twist gene (cTwist) and examined its expression pattern during development by whole mount in situ hybridization. In early embryos, cTwist transcripts are found in the developing somites, lateral plate mesoderm, limb mesenchyme, branchial arches and head mesenchyme. At later stages, cTwist expression is found in the sclerotome and dermatome, limb bud mesenchyme, interdigital regions, and distal mesenchyme of the maxillary and mandibular processes. In the developing feathers, cTwist is expressed in the mesenchyme of the buds and becomes restricted to the proximal region of the feather filaments. Additionally, we report that the expression of cTwistin the limb mesenchyme is regulated by the AER, FGFs, RA and SHH. The FGFs secreted by the AER seem to have a critical role in maintaining cTwist expression. SHH is also able to maintain cTwist expression but only in the presence of the AER. Overall, our results provide new evidence that reinforce the existence of an interplay between the cTwist and FGF signalling pathways.
我们分离出了鸡的Twist基因（cTwist），并通过全胚胎原位杂交技术研究了其在发育过程中的表达模式。在早期胚胎中，cTwist转录本在发育中的体节、侧板中胚层、肢体间充质、鳃弓和头部间充质中被发现。在后期阶段，cTwist表达出现在硬骨节和生皮节、肢体芽间充质、指间区域以及上颌和下颌突的远端间充质中。在发育中的羽毛中，cTwist在芽的间充质中表达，并局限于羽丝的近端区域。此外，我们报告称，cTwist在肢体间充质中的表达受顶外胚层嵴（AER）、成纤维细胞生长因子（FGFs）、视黄酸（RA）和音猬因子（SHH）的调控。AER分泌的FGFs似乎在维持cTwist表达方面起着关键作用。SHH也能够维持cTwist表达，但仅在有AER存在的情况下。总体而言，我们的结果提供了新的证据，强化了cTwist与FGF信号通路之间存在相互作用的观点。
