Common transcriptional mechanisms for visual photoreceptor cell differentiation among Pancrustaceans.
Common transcriptional mechanisms for visual photoreceptor cell differentiation among Pancrustaceans.
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DOI：
10.1371/journal.pgen.1004484
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发表时间：
2014-07
期刊：
影响因子：
4.5
通讯作者：
Zelhof AC
中科院分区：
文献类型：
--
作者：
Mahato S;Morita S;Tucker AE;Liang X;Jackowska M;Friedrich M;Shiga Y;Zelhof AC
视觉横纹肌光感受器的一个标志是横纹肌视蛋白的表达和独特的相关光导分子，这些分子被纳入一个特殊的扩展的顶端膜，横纹肌。鉴于横纹肌光感受器在原造口动物眼中的广泛利用，本文探讨横纹肌光感受器的分化是否存在共同的转录机制。在果蝇中，转录因子Pph13和Orthodenticle （Otd）指导着横纹肌视蛋白转录和横纹肌形态发生这两个方面的分化。我们证明了这两种蛋白的同源物在远亲节肢动物Tribolium castaneum和Daphnia magna的视觉系统中表达，并且它们在这些物种中的功能作用是相似的。特别是，我们确定了Pph13同源物能够结合红紫质核心序列I的一部分位点，这些位点存在于Tribolium和Daphnia的关键光转导基因中。此外，Pph13和Otd同源基因能够执行光感受器分化的深度保守功能，这可以通过挽救它们各自的果蝇突变表型来证明。在果蝇中，Pph13同源物在指导横纹肌形态发生和视蛋白表达方面的能力是相同的，而Otd同源物在调节光感受器分化方面表现出不同的能力。最后，Tribolium的功能缺失分析证实了Pph13和Otd在调节横纹肌视蛋白转录和横纹肌形态发生方面的保守要求。综上所述，我们的数据确定了横纹肌光感受器分化调控框架的组成部分，为定义横纹肌光感受器分化的祖先调控模块提供了基础。视觉系统由两种基本类型的光感受器组成，睫状体和横纹肌。每种光感受器类型由表达的视蛋白分子和适应于光转导机制的最终形态来定义。在这里，我们讨论了横纹肌光感受器分化是否存在共同的转录机制。我们证明了果蝇的两个同源转录因子Pph13和Orthodenticle在pancrustaceae， Tribolium（红粉甲虫）和Daphnia（水蚤）的光感受器中表达，并且能够执行横纹肌光感受器分化的保守功能。特别是，Tribolium和Daphnia同源体能够替代和挽救相应果蝇突变体中观察到的光感受器分化缺陷。此外，对Tribolium中Pph13和正畸基因的功能缺失分析表明，它们调节视蛋白转录和光感受器顶膜的形态发生。我们的数据阐明了横纹肌光感受器分化的框架，并为定义横纹肌分化的祖先调节模块和横纹肌光感受器功能多样性的潜在修饰提供了基础。
A hallmark of visual rhabdomeric photoreceptors is the expression of a rhabdomeric opsin and uniquely associated phototransduction molecules, which are incorporated into a specialized expanded apical membrane, the rhabdomere. Given the extensive utilization of rhabdomeric photoreceptors in the eyes of protostomes, here we address whether a common transcriptional mechanism exists for the differentiation of rhabdomeric photoreceptors. In Drosophila, the transcription factors Pph13 and Orthodenticle (Otd) direct both aspects of differentiation: rhabdomeric opsin transcription and rhabdomere morphogenesis. We demonstrate that the orthologs of both proteins are expressed in the visual systems of the distantly related arthropod species Tribolium castaneum and Daphnia magna and that their functional roles are similar in these species. In particular, we establish that the Pph13 homologs have the ability to bind a subset of Rhodopsin core sequence I sites and that these sites are present in key phototransduction genes of both Tribolium and Daphnia. Furthermore, Pph13 and Otd orthologs are capable of executing deeply conserved functions of photoreceptor differentiation as evidenced by the ability to rescue their respective Drosophila mutant phenotypes. Pph13 homologs are equivalent in their ability to direct both rhabdomere morphogenesis and opsin expression within Drosophila, whereas Otd paralogs demonstrate differential abilities to regulate photoreceptor differentiation. Finally, loss-of-function analyses in Tribolium confirm the conserved requirement of Pph13 and Otd in regulating both rhabdomeric opsin transcription and rhabdomere morphogenesis. Taken together, our data identify components of a regulatory framework for rhabdomeric photoreceptor differentiation in Pancrustaceans, providing a foundation for defining ancestral regulatory modules of rhabdomeric photoreceptor differentiation. Visual systems are populated by one of two fundamental types of photoreceptors, ciliary and rhabdomeric. Each photoreceptor type is defined by the opsin molecule expressed and the final morphological form adapted to house the phototransduction machinery. Here we address whether a common transcriptional mechanisms exists for the differentiation of rhabdomeric photoreceptors. We demonstrate that orthologs of two Drosophila (fruit fly) transcription factors, Pph13 and Orthodenticle, are expressed in photoreceptors of Pancrustaceans, Tribolium (red flour beetle) and Daphnia (water flea), and are capable of executing conserved functions of rhabdomeric photoreceptor differentiation. In particular, Tribolium and Daphnia orthologs are capable of substituting and rescuing the photoreceptor differentiation defects observed in their corresponding Drosophila mutants. Furthermore, loss of function analysis in Tribolium of both Pph13 and orthodenticle genes demonstrate they regulate opsin transcription and morphogenesis of the photoreceptor apical membrane. Our data illuminate a framework for rhabdomeric photoreceptor differentiation and provide the foundation for defining the ancestral regulatory modules for rhabdomeric differentiation and potential modifications that underlie the functional diversity observed in rhabdomeric photoreceptors.
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DOI：
10.1016/j.cub.2009.12.006
发表时间：
2010-02-09
期刊：
Current biology : CB
影响因子：
--
作者：
Fain GL;Hardie R;Laughlin SB
通讯作者：
Laughlin SB
影响因子：
16.2
作者：
Chen, SM;Wang, QL;Zack, DJ
通讯作者：
Zack, DJ
影响因子：
12.3
作者：
Gentleman RC;Carey VJ;Bates DM;Bolstad B;Dettling M;Dudoit S;Ellis B;Gautier L;Ge Y;Gentry J;Hornik K;Hothorn T;Huber W;Iacus S;Irizarry R;Leisch F;Li C;Maechler M;Rossini AJ;Sawitzki G;Smith C;Smyth G;Tierney L;Yang JY;Zhang J
通讯作者：
Zhang J
影响因子：
17.3
作者：
Gaj, Thomas;Gersbach, Charles A.;Barbas, Carlos F., III
通讯作者：
Barbas, Carlos F., III
影响因子：
25
作者：
Gooley, JJ;Lu, J;Saper, CB
通讯作者：
Saper, CB