Xu P, Sun B, Salvaterra P M
City of Hope Graduate School of Biological Sciences, Beckman Research Institute of the City of Hope, 1450 E. Duarte Road, Duarte, CA 91010, USA.
Gene. 1999 Aug 20;236(2):303-13. doi: 10.1016/s0378-1119(99)00269-3.
Drosophila melanogaster has two Na(+),K(+)-ATPase beta subunit genes (Nervana 1 and 2; Nrv), with tissue-specific expression patterns. Nrv1 produces a single beta subunit isoform expressed primarily in muscle tissue, whereas Nrv2 codes for two different isoforms (2.1 and 2.2) expressed in the nervous system. We have determined the complete molecular genomic organization for both Nrv genes. Only 3kb of DNA separate the 3' end of Nrv2 from Nrv1. The cDNAs from all three forms of Nrv have been mapped onto the genomic structure and all intron-exon junctions have been confirmed by direct sequencing. The genomic DNA positioned in the 5' flanking region of each Nrv gene has also been tested for tissue-specific transcriptional regulatory activity. P-element transformation vectors were constructed, which contained either 7.7kb of Nrv2 or 3.5kb Nrv1 5' flanking DNA driving expression of a lacZ reporter gene. Multiple transgenic Drosophila lines were established for each construct and analyzed for their beta-galactosidase expression pattern. The tissue-specific expression of each Nrv gene is independently regulated by the cis-element(s) present in the 5' flanking region. The Nrv2 5' flanking DNA directs expression exclusively to the nervous system, whereas Nrv1 5' flanking DNA directs expression primarily in muscle tissue.
黑腹果蝇有两个钠钾ATP酶β亚基基因（Nervana 1和2；Nrv），具有组织特异性表达模式。Nrv1产生一种主要在肌肉组织中表达的单一β亚基异构体，而Nrv2编码两种在神经系统中表达的不同异构体（2.1和2.2）。我们已经确定了这两个Nrv基因的完整分子基因组结构。Nrv2的3'端与Nrv1仅相隔3kb的DNA。来自Nrv三种形式的cDNA已定位到基因组结构上，所有内含子-外显子连接均通过直接测序得到确认。每个Nrv基因5'侧翼区域的基因组DNA也已进行组织特异性转录调控活性测试。构建了P-因子转化载体，其包含驱动lacZ报告基因表达的7.7kb的Nrv2或3.5kb的Nrv1 5'侧翼DNA。为每个构建体建立了多个转基因果蝇品系，并分析了它们的β-半乳糖苷酶表达模式。每个Nrv基因的组织特异性表达由5'侧翼区域中存在的顺式元件独立调控。Nrv2的5'侧翼DNA仅将表达导向神经系统，而Nrv1的5'侧翼DNA主要将表达导向肌肉组织。
