Salty dog, an SLC5 symporter, modulates Drosophila response to salt stress.
Salty dog, an SLC5 symporter, modulates Drosophila response to salt stress.
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DOI：
10.1152/physiolgenomics.90360.2008
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发表时间：
2009-03
影响因子：
4.6
通讯作者：
K. Stergiopoulos;P. Cabrero;S. Davies;J. Dow
中科院分区：
文献类型：
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作者：
K. Stergiopoulos;P. Cabrero;S. Davies;J. Dow
为了调节内部环境，生物体必须适应饮食中不同的离子水平。成年果蝇暴露于饮食盐胁迫，和他们的生理，生存和基因表达的反应进行监测。昆虫继续以NaCl升高的饮食为食，尽管> 4%wt/vol的水平最终被证明是致命的。对喂食含高NaCl饮食的果蝇进行的Affyphin微阵列分析显示了一个阶段性反应：最早的反应是免疫基因的广泛上调，随后是碳水化合物代谢的上调，因为免疫反应被下调，最后是氨基酸催化剂和生殖轴相关基因的抑制。值得注意的是，在线转录组学资源FlyAtlas报告说，大多数受调节的基因主要在后肠或Malpighian（肾）小管中表达，暗示这些排泄组织是盐胁迫的主要反应者。选择了三个基因进行进一步的研究：SLC 5同向转运体CG 2196，GLUT转运体CG 6484和转录因子sugarbabe（以前与饥饿和应激反应有关）。通过定量PCR（qPCR）验证微阵列预测的表达谱;通过原位杂交将表达映射到消化道。CG 2196：：eYFP过表达构建体定位于马尔皮基管（肾）小管的基底外侧膜，针对CG 2196的RNA干扰改善了高盐饮食的生存，即使是专门驱动至马尔皮基管的主细胞，也证实了这种组织和这种转运蛋白是盐应激下生存的主要决定因素。因此，CG 2196被重新命名为盐狗（salt dog）。
To regulate their internal environments, organisms must adapt to varying ion levels in their diet. Adult Drosophila were exposed to dietary salt stress, and their physiological, survival, and gene expression responses monitored. Insects continued to feed on NaCl-elevated diet, although levels >4% wt/vol ultimately proved fatal. Affymetrix microarray analysis of flies fed on diet containing elevated NaCl showed a phased response: the earliest response was widespread upregulation of immune genes, followed by upregulation of carbohydrate metabolism as the immune response was downregulated, then finally a switch to amino acid catabolism and inhibition of genes associated with the reproductive axis. Significantly, the online transcriptomic resource FlyAtlas reports that most of the modulated genes are predominantly expressed in hindgut or Malpighian (renal) tubule, implicating these excretory tissues as the major responders to salt stress. Three genes were selected for further study: the SLC5 symporter CG2196, the GLUT transporter CG6484, and the transcription factor sugarbabe (previously implicated in starvation and stress responses). Expression profiles predicted by microarray were validated by quantitative PCR (qPCR); expression was mapped to the alimentary canal by in situ hybridization. CG2196::eYFP overexpression constructs were localized to the basolateral membrane of the Malpighian (renal) tubules, and RNAi against CG2196 improved survival on high-salt diet, even when driven specifically to just principal cells of the Malpighian tubule, confirming both this tissue and this transporter as major determinants of survival upon salt stress. Accordingly, CG2196 was renamed salty dog (salt).