Zhao Zhongying, Sheps Jonathan A, Ling Victor, Fang Lily L, Baillie David L
Department of Molecular Biology and Biochemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC, Canada V5A 1S6.
J Mol Biol. 2004 Nov 19;344(2):409-17. doi: 10.1016/j.jmb.2004.09.052.
We have previously identified 60 predicted ABC transporter genes in the Caenorhabditis elegans genome and classified them into eight groups. As an initial step towards understanding how these putative ABC genes work in worms, we generated promoter-fluorescent protein fusions for the entire family to address when and where these genes are turned on in vivo. Both Aequoria green fluorescent protein (GFP) and Discosoma red fluorescent protein (RFP) were used as reporters in our transgenic assay. Observable expression is more frequently seen from fusions to genes in subfamilies B, C, D and E than those in subfamilies A and G. Sixteen worm ABC genes are found in tandem duplications, forming two four-gene clusters and four two-gene clusters. Fifteen out of the 16 duplicated gene promoters drove different or partially overlapping expression patterns, suggesting active functions for these duplicated genes. Furthermore, our results suggest that an internal promoter can cause differential expression of genes within an operon. Finally, our observations suggest that it is possible for coding sequences to function as a regulatory region for a neighbouring gene.
我们之前在秀丽隐杆线虫基因组中鉴定出60个预测的ABC转运蛋白基因，并将它们分为八组。作为了解这些假定的ABC基因在蠕虫中如何发挥作用的第一步，我们为整个家族构建了启动子-荧光蛋白融合体，以确定这些基因在体内何时何地被激活。在我们的转基因实验中，水母绿色荧光蛋白（GFP）和盘基网柄菌红色荧光蛋白（RFP）都被用作报告基因。与A和G亚家族中的基因融合相比，在B、C、D和E亚家族的基因融合中更频繁地观察到可观察到的表达。16个线虫ABC基因以串联重复的形式存在，形成了两个四基因簇和四个双基因簇。16个重复基因启动子中的15个驱动了不同或部分重叠的表达模式，表明这些重复基因具有活跃的功能。此外，我们的结果表明内部启动子可导致操纵子内基因的差异表达。最后，我们的观察结果表明编码序列有可能作为邻近基因的调控区域发挥作用。
