Comparison of gene expression during in vivo and in vitro postnatal retina development.

Retina explants are widely used as a model of neural development. To define the molecular basis of differences between the development of retina in vivo and in vitro during the early postnatal period, we carried out a series of microarray comparisons using mouse retinas. About 75% of 8,880 expressed genes from retina explants kept the same expression volume and pattern as the retina in vivo. Fewer than 6% of the total gene population was changed at two consecutive time points, and only about 1% genes showed more than a threefold change at any time point studied. Functional Gene Ontology (GO) mapping for both changed and unchanged genes showed similar distribution patterns, except that more genes were changed in the GO clusters of response to stimuli and carbohydrate metabolism. Three distinct expression patterns of genes preferentially expressed in rod photoreceptors were observed in the retina explants. Some genes showed a lag in increased expression, some showed no change, and some continued to have a reduced level of expression. An early downregulation of cyclin D1 in the explanted retina might explain the reduction in numbers of precursors in explanted retina and suggests that external factors are required for maintenance of cyclin D1. The global view of gene profiles presented in this study will help define the molecular changes in retina explants over time and will provide criteria to define future changes that improve this model system. The online version of this article (doi:10.1007/s12177-008-9009-z) contains supplementary material, which is available to authorized users.

视网膜外植体被广泛用作神经发育的模型。为了确定出生后早期体内和体外视网膜发育差异的分子基础，我们使用小鼠视网膜进行了一系列微阵列比较。在来自视网膜外植体的8880个表达基因中，约75%保持了与体内视网膜相同的表达量和模式。在连续两个时间点，总基因群中少于6%发生了变化，并且在研究的任何时间点只有约1%的基因表现出超过三倍的变化。对发生变化和未发生变化的基因进行的功能基因本体论（GO）映射显示出相似的分布模式，只是在对刺激的反应和碳水化合物代谢的GO簇中有更多基因发生了变化。在视网膜外植体中观察到了在视杆光感受器中优先表达的基因的三种不同表达模式。一些基因在表达增加方面出现延迟，一些没有变化，一些则持续处于较低的表达水平。外植视网膜中细胞周期蛋白D1的早期下调可能解释了外植视网膜中前体细胞数量的减少，并表明维持细胞周期蛋白D1需要外部因素。本研究中呈现的基因图谱的全局视图将有助于确定视网膜外植体随时间的分子变化，并将为确定改善该模型系统的未来变化提供标准。 本文的在线版本（doi:10.1007/s12177 - 008 - 9009 - z）包含补充材料，可供授权用户使用。