Collins Michelle M, Baumholtz Amanda I, Ryan Aimee K
Department of Human Genetics, Montréal, Québec, Canada H3Z 2Z3; The Research Institute of the McGill University Health Centre, Montréal, Québec, Canada H3Z 2Z3.
Department of Human Genetics, Montréal, Québec, Canada H3Z 2Z3; Department of Pediatrics, McGill University, Montréal, Québec, Canada H3Z 2Z3; The Research Institute of the McGill University Health Centre, Montréal, Québec, Canada H3Z 2Z3.
Gene Expr Patterns. 2012 Mar-Apr;12(3-4):123-9. doi: 10.1016/j.gep.2012.01.005. Epub 2012 Feb 3.
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. Studies in human, mouse, Xenopus, and zebrafish have shown that only a limited number of claudins are expressed in endothelial cells. Here, we report the expression pattern of Claudin-5 during chick development. Between HH stage 4 and 6 Claudin-5 expression was observed exclusively in extraembryonic tissue. Claudin-5 expression was not observed in the embryo until HH stage 8, coincident with the onset of embryonic vascularization. Claudin-5 expression was maintained in the developing vasculature in the embryonic and extraembryonic tissue throughout organogenesis (HH stage 19-35), including the vasculature of the ectoderm and of organs derived from the mesoderm and endoderm lineages. These data describe a conserved expression pattern for Claudin-5 in the endothelial tight junction barrier and is the first report of the onset of Claudin-5 expression in a vertebrate embryo.
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中细胞旁转运的离子特异性和通透性。对人类、小鼠、非洲爪蟾和斑马鱼的研究表明，内皮细胞中仅表达有限数量的紧密连接蛋白。在此，我们报告了紧密连接蛋白5在鸡胚胎发育过程中的表达模式。在鸡胚发育的第4至6期，紧密连接蛋白5仅在胚外组织中表达。直到鸡胚发育的第8期，胚胎血管开始形成时，才在胚胎中观察到紧密连接蛋白5的表达。在整个器官发生过程（鸡胚发育的第19至35期）中，紧密连接蛋白5在胚胎和胚外组织的发育血管中持续表达，包括外胚层以及源自中胚层和内胚层谱系的器官的血管。这些数据描述了紧密连接蛋白5在内皮紧密连接屏障中的保守表达模式，这也是脊椎动物胚胎中紧密连接蛋白5表达起始的首次报道。
