Vihtelic Thomas S
Department of Biological Sciences and Center for Zebrafish Research, Galvin Life Sciences Center, University of Notre Dame, Notre Dame, Indiana 46556, USA.
Int Rev Cell Mol Biol. 2008;269:341-73. doi: 10.1016/S1937-6448(08)01006-X.
The transparent properties of the lens and its ability to focus light onto the retina are critical for normal vision. Optical clarity of the lens is achieved and maintained by a unique, highly regulated integration of lens cell proliferation and differentiation that persists throughout life. Zebrafish is a powerful genetic model for studying vertebrate lens differentiation and growth because the structural organization of the lens and gene functions are largely conserved with mammals, including humans. However, some features of zebrafish lens developmental morphology and gene expression are different from those of mammals and other terrestrial vertebrates. For example, the presumptive zebrafish lens delaminates from the surface ectoderm to form a solid mass of cells, in which the primary fibers differentiate by elongating in circular fashion. Both mutational and candidate gene analyses have identified and characterized developmental gene functions of the lens in zebrafish. This chapter presents the recent morphological analysis of zebrafish lens formation. In addition, the roles of Pitx3, Foxe3, and the lens-specific protein Lengsin (LENS Glutamine SYNthetase-like) in lens development are analyzed. Selected zebrafish lens mutants defective in early developmental processes and the maintenance of lens transparency are also discussed.
晶状体的透明特性及其将光线聚焦到视网膜上的能力对于正常视力至关重要。晶状体的光学清晰度是通过晶状体细胞增殖和分化的独特、高度调控的整合来实现和维持的，这种整合在整个生命过程中持续存在。斑马鱼是研究脊椎动物晶状体分化和生长的强大遗传模型，因为晶状体的结构组织和基因功能在很大程度上与包括人类在内的哺乳动物保守。然而，斑马鱼晶状体发育形态和基因表达的一些特征与哺乳动物和其他陆生脊椎动物不同。例如，推定的斑马鱼晶状体从表面外胚层分层形成一团实体细胞，其中初级纤维通过以圆形方式伸长而分化。突变分析和候选基因分析都已鉴定并表征了斑马鱼晶状体的发育基因功能。本章介绍了斑马鱼晶状体形成的最新形态学分析。此外，还分析了Pitx3、Foxe3和晶状体特异性蛋白Lengsin（晶状体谷氨酰胺合成酶样蛋白）在晶状体发育中的作用。还讨论了在早期发育过程和晶状体透明度维持方面存在缺陷的选定斑马鱼晶状体突变体。
