University of Washington, Department of Biological Structure, Seattle, WA 98195, USA.
Development. 2010 Feb;137(4):619-29. doi: 10.1242/dev.043968.
Photoreceptors, rods and cones are the most abundant cell type in the mammalian retina. However, the molecules that control their development are not fully understood. In studies of photoreceptor fate determination, we found that Blimp1 (Prdm1) is expressed transiently in developing photoreceptors. We analyzed the function of Blimp1 in the mouse retina using a conditional deletion approach. Developmental analysis of mutants showed that Otx2(+) photoreceptor precursors ectopically express the bipolar cell markers Chx10 (Vsx2) and Vsx1, adopting bipolar instead of photoreceptor fate. However, this fate shift did not occur until the time when bipolar cells are normally specified during development. Most of the excess bipolar cells died around the time of bipolar cell maturation. Our results suggest that Blimp1 expression stabilizes immature photoreceptors by preventing bipolar cell induction. We conclude that Blimp1 regulates the decision between photoreceptor and bipolar cell fates in the Otx2(+) cell population during retinal development.
光感受器、视杆细胞和视锥细胞是哺乳动物视网膜中最丰富的细胞类型。然而，控制它们发育的分子还不完全清楚。在对光感受器命运决定的研究中，我们发现 Blimp1（Prdm1）在发育中的光感受器中短暂表达。我们使用条件性缺失方法分析了 Blimp1 在小鼠视网膜中的功能。对突变体的发育分析表明，Otx2(+)光感受器前体细胞异位表达双极细胞标记物 Chx10 (Vsx2) 和 Vsx1，采用双极而不是光感受器命运。然而，这种命运转变直到在发育过程中正常指定双极细胞的时间才发生。大多数多余的双极细胞在双极细胞成熟时死亡。我们的结果表明，Blimp1 的表达通过阻止双极细胞诱导来稳定不成熟的光感受器。我们得出结论，Blimp1 在视网膜发育过程中调节 Otx2(+)细胞群体中光感受器和双极细胞命运之间的决定。
