Collins Michelle M, Baumholtz Amanda I, Ryan Aimee K
Department of Human Genetics; McGill University; Montréal, QC Canada ; Research Institute of the McGill University Health Centre; Montréal, QC Canada.
Department of Human Genetics; McGill University; Montréal, QC Canada ; Research Institute of the McGill University Health Centre; Montréal, QC Canada ; Department of Pediatrics; McGill University; Montréal, QC Canada.
Tissue Barriers. 2013 Jul 1;1(3):e24517. doi: 10.4161/tisb.24517. Epub 2013 Apr 10.
The claudin family of proteins are integral components of tight junctions and are responsible for determining the ion specificity and permeability of paracellular transport within epithelial and endothelial cell layers. Several members of the claudin family have been shown to be important during embryonic development and morphogenesis. However, detailed embryonic expression patterns have been described for only a few claudins. Here, we provide a phylogenetic analysis of the chicken claudins and a comprehensive analysis of their mRNA expression profiles. We found that claudin family members exhibit both overlapping and unique expression patterns throughout development. Especially striking were the distinct expression boundaries observed between neural and non-neural ectoderm, as well as within ectodermal derivatives. Claudins were also expressed in endodermally-derived tissues, including the anterior intestinal portal, pharynx, lung and pancreas and in mesodermally derived tissues such as the kidney, gonad and heart. The overlapping zones of claudin expression observed in the chick embryo may confer distinct domains of ion permeability within the early epiblast and in epithelial, mesodermal and endothelial derivatives that may ultimately influence embryonic patterning and morphogenesis during development.
紧密连接蛋白家族是紧密连接的重要组成部分，负责决定上皮细胞层和内皮细胞层间细胞旁转运的离子特异性和通透性。紧密连接蛋白家族的几个成员已被证明在胚胎发育和形态发生过程中很重要。然而，只有少数紧密连接蛋白的详细胚胎表达模式被描述过。在这里，我们对鸡的紧密连接蛋白进行了系统发育分析，并对它们的mRNA表达谱进行了全面分析。我们发现，紧密连接蛋白家族成员在整个发育过程中表现出重叠和独特的表达模式。特别显著的是，在神经外胚层和非神经外胚层之间以及在外胚层衍生物内部观察到明显的表达边界。紧密连接蛋白也在内胚层来源的组织中表达，包括前肠门、咽、肺和胰腺，以及中胚层来源的组织，如肾脏、性腺和心脏。在鸡胚中观察到的紧密连接蛋白表达重叠区域，可能在早期上胚层以及上皮、中胚层和内皮衍生物中赋予不同的离子通透区域，这最终可能影响发育过程中的胚胎模式形成和形态发生。
