Development. Limb cells don't tell time.
Development. Limb cells don't tell time.
复制标题
发展。
DOI：
10.1126/science.1207554
复制
发表时间：
2011
期刊：
影响因子：
--
通讯作者：
Lewandoski,Mark
中科院分区：
文献类型：
--
作者：
Mackem,Susan;Lewandoski,Mark
虽然肢体发育是研究图案形成和形态发生的最佳模型之一，但控制其顺序的近端到远端，肩到指尖形成的机制仍然存在争议。根据“进展区”模型，肢体祖细胞通过内部时钟机制逐渐“远端化”，该机制跟踪在来自远端肢体芽边缘的允许成纤维细胞生长因子（FGF）信号的影响下花费的时间，尽管最近的工作挑战了这一想法。替代模型提出，近端信号可以指示近端-远端细胞的命运，从而避免了对细胞自主时钟的需要。本期的两篇论文，Cooperet等人在第1083页和Roselló-Díezet等人在第1086页，支持后一种模型，并表明近端视黄酸（RA）信号传导和远端FGF活性之间的动态平衡决定了小鸡主要肢节的近端-远端模式。组合信号还维持肢芽细胞的近端-远端可塑性和祖细胞状态。肢体发育中的这些信号作用让人想起肢体再生过程中的事件，表明两者之间的吝啬程度比以前认为的要高。
Although limb development is one of the best models to study pattern formation and morphogenesis, the mechanisms that control its sequential proximal-to-distal, shoulder to finger tip formation have remained controversial . According to the “progress zone” model, limb progenitor cells become progressively “distalized” in identity via an internal clock mechanism that tracks time spent under the influence of permissive fibroblast growth factor (FGF) signals from the distal limb bud margin, although recent work has challenged this idea . Alternative models propose that proximal signals could instruct proximal-distal cell fate, obviating the need for a cell-autonomous clock. Two papers in this issue, by Cooperet al.on page 1083 and Roselló-Díezet al.on page 1086, support the latter model and show that the dynamic balance between proximal retinoic acid (RA) signaling and distal FGF activity governs the proximal-distal pattern of major limb segments in the chick. Combined signals also maintain the proximal-distal plasticity and progenitor state of limb bud cells. These signaling roles in limb development are reminiscent of events during limb regeneration, suggesting a higher level of parsimony between the two than once thought.