ANALYSIS OF CIS-ACTING REQUIREMENTS OF THE RH3 AND RH4 GENES REVEALS A BIPARTITE ORGANIZATION TO RHODOPSIN PROMOTERS IN DROSOPHILA-MELANOGASTER
ANALYSIS OF CIS-ACTING REQUIREMENTS OF THE RH3 AND RH4 GENES REVEALS A BIPARTITE ORGANIZATION TO RHODOPSIN PROMOTERS IN DROSOPHILA-MELANOGASTER
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DOI：
10.1101/gad.4.3.444
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发表时间：
1990-03-01
影响因子：
10.5
通讯作者：
RUBIN, GM
中科院分区：
文献类型：
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作者：
FORTINI, ME;RUBIN, GM
黑腹果蝇的视紫红质基因在昆虫视觉系统内的感光细胞的非重叠亚群中表达。其中两个基因，Rh3 和 Rh4，已知在复眼的紫外线敏感 R7 感光细胞群中表现出互补的表达模式。此外，我们发现 Rh3 在眼背边缘的一小群成对的 R7 和 R8 感光细胞中表达，这些细胞显然专门用于检测偏振光。在本文中，我们详细描述了 Rh3 和 Rh4 的顺式作用要求。启动子删除系列表明，两个 R7 视蛋白基因的小调控区 (< 300 bp) 包含足以产生各自表达模式的 DNA 序列。通过种间序列比较指导的寡核苷酸定向诱变进一步鉴定了各个顺式作用元件。我们的结果表明，Droposphila 视紫红质基因共享一个简单的二分启动子结构，其中近端区域构成功能等效的启动子“核心”，远端区域决定细胞类型特异性。几种混合视紫红质启动子的表达模式（其中全部或部分推定核心区域已被不同视紫红质启动子的类似区域取代）提供了支持该模型的额外证据。
The rhodopsin genes of Drosophila melanogaster are expressed in nonoverlapping subsets of photoreceptor cells within the insect visual system. Two of these genes, Rh3 and Rh4, are known to display complementary expression patterns in the UV-sensitive R7 photoreceptor cell population of the compound eye. In addition, we find that Rh3 is expressed in a small group of paired R7 and R8 photoreceptor cells at the dorsal eye margin that are apparently specialized for the detection of polarized light. In this paper we present a detailed characterization of the cis-acting requirements of both Rh3 and Rh4. Promoter deletion series demonstrate that small regulatory regions (< 300 bp) of both R7 opsin genes contain DNA sequences sufficient to generate their respective expression patterns. Individual cis-acting elements were further identified by oligonucleotide-directed mutagenesis guided by interspecific sequence comparisons. Our results suggest that the Droposphila rhodopsin genes share a simple bipartite promoter structure, whereby the proximal region constitutes a functionally equivalent promoter "core" and the distal region determines cell-type specificity. The expression patterns of several hybrid rhodopsin promoters, in which all or part of the putative core regions have been replaced with the analogous regions of different rhodopsin promoters, provide additional evidence in support of this model.