Department of Pharmacology, and Silvio O. Conte Center for Neuroscience Research, Vanderbilt University School of Medicine, Nashville, TN 37232-8548, USA.
G3 (Bethesda). 2012 Aug;2(8):961-75. doi: 10.1534/g3.112.003533. Epub 2012 Aug 1.
Disrupted dopamine (DA) signaling is believed to contribute to the core features of multiple neuropsychiatric and neurodegenerative disorders. Essential features of DA neurotransmission are conserved in the nematode Caenorhabditis elegans, providing us with an opportunity to implement forward genetic approaches that may reveal novel, in vivo regulators of DA signaling. Previously, we identified a robust phenotype, termed Swimming-induced paralysis (Swip), that emerges in animals deficient in the plasma membrane DA transporter. Here, we report the use and quantitative analysis of Swip in the identification of mutant genes that control DA signaling. Two lines captured in our screen (vt21 and vt22) bear novel dat-1 alleles that disrupt expression and surface trafficking of transporter proteins in vitro and in vivo. Two additional lines, vt25 and vt29, lack transporter mutations but exhibit genetic, biochemical, and behavioral phenotypes consistent with distinct perturbations of DA signaling. Our studies validate the utility of the Swip screen, demonstrate the functional relevance of DA transporter structural elements, and reveal novel genomic loci that encode regulators of DA signaling.
多巴胺（DA）信号的紊乱被认为是导致多种神经精神和神经退行性疾病的核心特征之一。秀丽隐杆线虫（Caenorhabditis elegans）中的 DA 神经传递具有保守的基本特征，这为我们提供了一个机会，可以采用正向遗传学方法来揭示 DA 信号的新型、体内调节因子。此前，我们发现了一种称为游泳诱导瘫痪（Swip）的强表型，这种表型出现在缺乏质膜 DA 转运体的动物中。在这里，我们报告了 Swip 在鉴定控制 DA 信号的突变基因中的应用和定量分析。我们的筛选中捕获到的两条品系（vt21 和 vt22）携带新的 dat-1 等位基因，这些等位基因在体外和体内破坏了转运蛋白的表达和表面转运。另外两条品系 vt25 和 vt29 没有转运突变，但表现出遗传、生化和行为表型，与 DA 信号的明显扰动一致。我们的研究验证了 Swip 筛选的实用性，证明了 DA 转运体结构元件的功能相关性，并揭示了新的基因组位点，这些位点编码 DA 信号的调节剂。
