Tight Junction Protein 1a regulates pigment cell organisation during zebrafish colour patterning.
Tight Junction Protein 1a regulates pigment cell organisation during zebrafish colour patterning.
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DOI：
10.7554/elife.06545
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发表时间：
2015-04-27
期刊：
影响因子：
7.7
通讯作者：
Nüsslein-Volhard C
中科院分区：
文献类型：
--
作者：
Fadeev A;Krauss J;Frohnhöfer HG;Irion U;Nüsslein-Volhard C
斑马鱼显示出一种由皮肤中色素细胞精确定位产生的明暗交替条纹的突出图案。这种排列是变态过程中协调细胞运动、细胞形状变化和色素细胞组织的结果。虹膜细胞在这个过程中起着至关重要的作用，它在密集的亮条纹和松散的暗条纹之间切换。成年schachbrett（sbr）突变体表现出延迟的虹膜的形状和组织的截断引起的紧密连接蛋白1a（ZO-1a）的变化。在sbr突变体中，深色条纹被密集的虹膜细胞作为连贯的片层侵入。免疫标记和嵌合分析表明，Tjp 1a是在密集的iridophores表达，但在松散的形式下调。tjp 1a是一种新的调节细胞形状变化的过程中的颜色图案的形成和第一个细胞质蛋白在这一过程中牵连。http://dx.doi.org/10.7554/eLife.06545.001斑马鱼引人注目的水平条纹图案使它成为许多家庭水族馆的装饰品。条纹是三种不同的色素细胞相互作用的结果，当动物两到三周大时，条纹开始出现。此时，称为虹膜细胞的虹彩细胞开始在皮肤中繁殖和扩散。在浅色条纹中，虹膜细胞是紧凑和“密集”的;在深色条纹中，细胞变成“松散”的形状和组织。黑色素细胞填充在深色条纹中，第三种细胞类型的黄色色调凝聚在浅色条纹上。这三种类型的细胞是如何协同工作形成条纹图案的，目前还不完全清楚。Fadeev等人研究了一种具有遗传突变的斑马鱼变体，该突变破坏了一种称为紧密连接蛋白1a（或Tjp 1a）的蛋白质的功能-一种称为ZO-1的哺乳动物蛋白质的鱼类变体。这种蛋白质帮助细胞相互作用。这种突变鱼看起来是斑点状的而不是条纹状的，这是因为含有密集虹彩细胞的浅色区域打断了深色条纹。使用荧光标记物的实验表明，Tjp 1a在暗条纹中的松散虹膜细胞中的产生量比在亮条纹中的密集虹膜细胞中的产生量低得多。这使得Fadeev等人提出，从致密到松散的形状的转变取决于细胞中Tjp 1a的存在。tjp 1a可能通过控制虹膜细胞与其他类型色素细胞的相互作用来调节颜色模式的形成。Tjp 1a突变鱼提供了对细胞内颜色模式形成机制的第一次一瞥，并将有助于识别负责细胞相互作用的其他成分和线索。DOI：http://dx.doi.org/10.7554/eLife.06545.002网站
Zebrafish display a prominent pattern of alternating dark and light stripes generated by the precise positioning of pigment cells in the skin. This arrangement is the result of coordinated cell movements, cell shape changes, and the organisation of pigment cells during metamorphosis. Iridophores play a crucial part in this process by switching between the dense form of the light stripes and the loose form of the dark stripes. Adult schachbrett (sbr) mutants exhibit delayed changes in iridophore shape and organisation caused by truncations in Tight Junction Protein 1a (ZO-1a). In sbr mutants, the dark stripes are interrupted by dense iridophores invading as coherent sheets. Immuno-labelling and chimeric analyses indicate that Tjp1a is expressed in dense iridophores but down-regulated in the loose form. Tjp1a is a novel regulator of cell shape changes during colour pattern formation and the first cytoplasmic protein implicated in this process. DOI: http://dx.doi.org/10.7554/eLife.06545.001 The striking horizontal striped pattern of the zebrafish makes it a decorative addition to many home aquariums. The stripes are a result of three different pigment cells interacting with each other, and first begin to emerge when the animal is two to three weeks old. At that time, iridescent cells called iridophores begin to multiply and spread in the skin. In the light-coloured stripes, the iridophores are compact and ‘dense’; in the dark stripes the cells change into a ‘loose’ shape and organisation. Black-pigmented cells fill in the dark stripes, and a third cell type with a yellow hue condenses over the light stripes. How the three types of cell work together to make the striped pattern is not fully understood. Fadeev et al. examined a zebrafish variant with a genetic mutation that disrupts the function of a protein called Tight Junction Protein 1a (or Tjp1a)—a fish variant of a mammalian protein called ZO-1. This protein helps cells to interact with each other. The mutant fish appear spotted rather than striped, because light regions containing sheets of the dense iridophores interrupt the dark stripes. Experiments using fluorescent markers showed that Tjp1a is produced in much lower amounts in the loose iridophores in the dark stripes than in the dense iridophores of the light stripes. This led Fadeev et al. to suggest that the transition from the dense to the loose shape is dependent on the presence of Tjp1a in the cell. Tjp1a is likely to regulate how colour patterns form by controlling how iridophores interact with other types of pigment cell. The Tjp1a mutant fish provides the first glimpse into the machinery inside cells that underlies colour pattern formation, and will help to identify other components and cues responsible for cell interactions. DOI: http://dx.doi.org/10.7554/eLife.06545.002