Redpath Museum, McGill University, 859 Sherbrooke St W, Montréal, QC, H3A 0C4, Canada; Department of Biology, McGill University, Stewart Biology Building, 1205 Docteur Penfield, Montréal, QC, H3A 1B1, Canada.
Redpath Museum, McGill University, 859 Sherbrooke St W, Montréal, QC, H3A 0C4, Canada.
Dev Biol. 2020 Jul 15;463(2):124-134. doi: 10.1016/j.ydbio.2020.04.009. Epub 2020 May 15.
Initial limb chondrogenesis offers the first differentiated tissues that resemble the mature skeletal anatomy. It is a developmental progression of three tissues. The limb begins with undifferentiated mesenchyme-1, some of which differentiates into condensations-2, and this tissue then transforms into cartilage-3. Each tissue is identified by physical characteristics of cell density, shape, and extracellular matrix composition. Tissue specific regimes of gene regulation underlie the diagnostic physical and chemical properties of these three tissues. These three tissue based regimes co-exist amid a background of other gene regulatory regimes within the same tissues and time-frame of limb development. The bio-molecular indicators of gene regulation reveal six identifiable patterns. Three of these patterns describe the unique bio-molecular indicators of each of the three tissues. A fourth pattern shares bio-molecular indicators between condensation and cartilage. Finally, a fifth pattern is composed of bio-molecular indicators that are found in undifferentiated mesenchyme prior to any condensation differentiation, then these bio-molecular indicators are upregulated in condensations and downregulated in undifferentiated mesenchyme. The undifferentiated mesenchyme that remains in between the condensations and cartilage, the interdigit, contains a unique set of bio-molecular indicators that exhibit dynamic behaviour during chondrogenesis and therefore argue for its own inclusion as a tissue in its own right and for more study into this process of differentiation.
初始肢体软骨发生提供了与成熟骨骼解剖结构相似的第一批分化组织。它是三个组织的发育进展。肢体首先从未分化的间充质 1 开始，其中一些分化成凝块 2，然后该组织转化为软骨 3。每种组织都通过细胞密度、形状和细胞外基质组成的物理特征来识别。组织特异性的基因调控机制是这三种组织的物理和化学特性的基础。在肢体发育的同一组织和时间框架内，这三种基于组织的调控机制与其他基因调控机制并存。基因调控的生物分子指标揭示了六个可识别的模式。其中三个模式描述了这三种组织各自独特的生物分子指标。第四个模式在软骨和软骨之间共享生物分子指标。最后，第五个模式由在任何凝块分化之前存在于未分化的间充质中的生物分子指标组成，然后这些生物分子指标在凝块中上调，在未分化的间充质中下调。在凝块和软骨之间的指间存在的未分化间充质，具有一组独特的生物分子指标，在软骨发生过程中表现出动态行为，因此主张将其自身作为一种组织包含在内，并对这一分化过程进行更多研究。
