Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37232, USA.
Development. 2012 Aug;139(16):2926-34. doi: 10.1242/dev.082396. Epub 2012 Jul 4.
Mesothelium is the surface layer of all coelomic organs and is crucial for the generation of their vasculature. Still, our understanding of the genesis of this essential cell type is restricted to the heart where a localized exogenous population of cells, the proepicardium, migrates to and envelops the myocardium supplying mesothelial, vascular and stromal cell lineages. Currently it is not known whether this pattern of development is specific to the heart or applies broadly to other coelomic organs. Using two independent long-term lineage-tracing studies, we demonstrate that mesothelial progenitors of the intestine are intrinsic to the gut tube anlage. Furthermore, a novel chick-quail chimera model of gut morphogenesis reveals these mesothelial progenitors are broadly distributed throughout the gut primordium and are not derived from a localized and exogenous proepicardium-like source of cells. These data demonstrate an intrinsic origin of mesothelial cells to a coelomic organ and provide a novel mechanism for the generation of mesothelial cells.
间皮是所有体腔器官的表面层，对于它们的脉管系统的生成至关重要。尽管如此，我们对这种重要细胞类型的起源的理解仅限于心脏，在心脏中，局部的外生细胞群体，即心外膜，迁移并包裹心肌，提供间皮、血管和基质细胞谱系。目前尚不清楚这种发育模式是否特定于心脏，或者是否广泛适用于其他体腔器官。使用两个独立的长期谱系追踪研究，我们证明了肠道的间皮祖先是肠道管胚的内在组成部分。此外，肠道形态发生的新型鸡-鹌鹑嵌合体模型表明，这些间皮祖细胞广泛分布在肠道原基中，并非来自局部的、外生的类心外膜细胞来源。这些数据表明体腔器官的间皮细胞具有内在起源，并为间皮细胞的生成提供了一种新的机制。
