Zebrafish genes rx1 and rx2 help define the region of forebrain that gives rise to retina
Zebrafish genes rx1 and rx2 help define the region of forebrain that gives rise to retina
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DOI：
10.1006/dbio.2000.0125
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发表时间：
2001-03-01
影响因子：
2.7
通讯作者：
Raymond, PA
中科院分区：
文献类型：
--
作者：
Chuang, JC;Raymond, PA
斑马鱼视网膜同源盒基因rx 1和rx 2只在视原基中表达，然后在分化的神经视网膜的视锥细胞中表达。在这项研究中，我们表明，在斑马鱼胚胎的神经板的公布的命运地图中，被确定为视网膜的区域costensive的表达结构域。视网膜和前脑前体之间的时空关系的分析表明，视网膜前体的横向运动是负责外翻的视原基。rx 1或rx 2的过度表达导致前脑组织的丢失和视网膜组织的异位形成。我们询问前脑的缺失和视网膜组织的扩张是否可以用端脑前体的死亡和视网膜前体的增殖增强来解释，我们发现不能。相反，我们的数据与前脑前体细胞命运的变化相一致，与端脑标志物（emx 1和BF-1）的表达减少和视网膜标志物（rx 1/2/3，pax 6，six 6和vsx 2）在神经龙骨阶段的异位表达相关。单独的rx 1同源结构域足以诱导异位视网膜组织，虽然弱，这一观察，连同缺失结构的结果，表明与未识别的转录调节因子的相互作用是重要的rx 1和rx 2功能在早期眼睛发育。我们的结论是，调节表达的斑马鱼rx 1和rx 2有助于确定该地区的前脑注定要引起视网膜组织，并可能参与细胞迁移，导致分裂的视网膜举行和形成的视原基。(C)北京：科学出版社.
Zebrafish retinal homeobox genes rx1 and rx2 are expressed exclusively in the optic primordia and then in cone photoreceptors of the differentiated neural retina. In this study, we show that the rx expression domain is coextensive with the region identified as the retinal held in published fate maps of the neural plate in zebrafish embryos. Analysis of the spatiotemporal relationships between retinal and forebrain precursors suggests that lateral movement of retinal precursors is responsible for evagination of the optic primordia. Overexpression of either rx1 or rx2 results in the loss of forebrain tissue and the ectopic formation of retinal tissue. We asked whether the deletion of forebrain and expansion of retinal tissue could be explained by the death of telencephalic precursors and enhanced proliferation of retinal precursors, and we found that it could not. Instead, our data are consistent with a change in cell fate of forebrain precursors associated with reduced expression of telencephalic markers (emx1 and BF-1) and ectopic expression of retinal markers (rx1/2/3, pax6, six6, and vsx2) at the neural keel stage. The rx homeodomain alone is sufficient to induce ectopic retinal tissue, although weakly so, and this observation, together with results from deletion constructs, suggests that interactions with unidentified transcriptional regulators are important for rx1 and rx2 function during early eye development. We conclude that regulated expression of zebrafish rx1 and rx2 helps to define the region of the forebrain fated to give rise to retinal tissue and may be involved in the cellular migrations that lead to splitting of the retinal held and formation of the optic primordia. (C) 2001 Academic Press.