Bernardo-Garcia F Javier, Fritsch Cornelia, Sprecher Simon G
Department of Biology, University of Fribourg, Fribourg 1700, Switzerland.
Department of Biology, University of Fribourg, Fribourg 1700, Switzerland
Development. 2016 Apr 15;143(8):1413-23. doi: 10.1242/dev.128801. Epub 2016 Mar 7.
Eye development requires an evolutionarily conserved group of transcription factors, termed the retinal determination network (RDN). However, little is known about the molecular mechanism by which the RDN instructs cells to differentiate into photoreceptors. We show that photoreceptor cell identity in Drosophila is critically regulated by the transcription factor Glass, which is primarily expressed in photoreceptors and whose role in this process was previously unknown. Glass is both required and sufficient for the expression of phototransduction proteins. Our results demonstrate that the RDN member Sine oculis directly activates glass expression, and that Glass activates the expression of the transcription factors Hazy and Otd. We identified hazy as a direct target of Glass. Induced expression of Hazy in the retina partially rescues the glass mutant phenotype. Together, our results provide a transcriptional link between eye field specification and photoreceptor differentiation in Drosophila, placing Glass at a central position in this developmental process.
眼睛发育需要一组进化上保守的转录因子，称为视网膜决定网络（RDN）。然而，关于RDN指导细胞分化为光感受器的分子机制，我们知之甚少。我们发现，果蝇中的光感受器细胞身份受转录因子Glass的严格调控，Glass主要在光感受器中表达，其在此过程中的作用此前未知。Glass对于光转导蛋白的表达既是必需的也是充分的。我们的结果表明，RDN成员眼缺直接激活glass的表达，并且Glass激活转录因子朦胧（Hazy）和无眼（Otd）的表达。我们确定朦胧是Glass的直接靶标。在视网膜中诱导表达朦胧可部分挽救glass突变体表型。总之，我们的结果在果蝇的眼场特化和光感受器分化之间提供了一个转录联系，使Glass在这个发育过程中处于核心位置。
