Institute for Behavioral Genetics, University of Colorado, Boulder, Colorado, USA.
Pharmacogenet Genomics. 2010 Sep;20(9):553-64. doi: 10.1097/FPC.0b013e32833d8c20.
Inbred long-sleep and short-sleep mice (ILS and ISS) were selectively bred for differential sensitivity to the sedative effects of ethanol. Lines of mice derived from these progenitors have been used to identify several quantitative trait loci (QTLs) mediating loss of the righting reflex due to ethanol (LORE). This study investigated the metabotropic glutamate receptor subtype 5 (mGluR5) as a candidate gene underlying Lore7, a QTL mediating differential LORE sensitivity.
We used knockout mice, a quantitative complementation test, pharmacological antagonism of mGluR5, real-time quantitative PCR, radioligand binding, DNA sequencing, and bioinformatics to examine the role of mGluR5 in ethanol-induced sedation.
mGluR5 knockout mice had a significantly longer LORE duration than wildtype controls. Administration of the mGluR5 antagonist 2-methyl-6-(phenylethyl)-pyridine (MPEP) had differential effects on LORE in ILS and ISS mice. A quantitative complementation test also supported mGluR5 mediating LORE. Two intronic single-nucleotide polymorphisms in mGluR5 were highly correlated with LORE in recombinant inbred mice derived from a cross between ILS and ISS (LXS RIs). Differences in mGluR5 mRNA level and receptor density were observed between ILS and ISS in distinct brain regions. Finally, data from WebQTL showed that mGluR5 expression was highly correlated with several LORE phenotypes in the LXS RIs.
Altogether, this data provides convincing evidence that mGluR5 mediates differential sensitivity to the sedative effects of ethanol. Studies from the human literature have also identified mGluR5 as a potential candidate gene for ethanol sensitivity.
通过对乙醇镇静作用的敏感性差异，对近交系长睡和短睡（ILS 和 ISS）小鼠进行选择性繁殖。从这些亲本衍生而来的小鼠系已被用于鉴定几种数量性状基因座（QTL），这些基因座介导由于乙醇导致的翻正反射丧失（LORE）。本研究调查了代谢型谷氨酸受体 5 型（mGluR5）作为介导 LORE 敏感性差异的 QTL Lore7 的候选基因。
我们使用了敲除小鼠、定量互补测试、mGluR5 的药理学拮抗作用、实时定量 PCR、放射性配体结合、DNA 测序和生物信息学，以研究 mGluR5 在乙醇诱导镇静中的作用。
mGluR5 敲除小鼠的 LORE 持续时间明显长于野生型对照。mGluR5 拮抗剂 2-甲基-6-（苯乙基）-吡啶（MPEP）对 ILS 和 ISS 小鼠的 LORE 有不同的影响。定量互补测试也支持 mGluR5 介导 LORE。mGluR5 中的两个内含子单核苷酸多态性与 ILS 和 ISS 杂交衍生的重组近交系（LXS RIs）中的 LORE 高度相关。在不同的脑区观察到 ILS 和 ISS 之间 mGluR5 mRNA 水平和受体密度的差异。最后，WebQTL 上的数据显示，mGluR5 表达与 LXS RIs 中的几种 LORE 表型高度相关。
总的来说，这些数据提供了令人信服的证据，表明 mGluR5 介导了对乙醇镇静作用的敏感性差异。人类文献中的研究也将 mGluR5 鉴定为乙醇敏感性的潜在候选基因。
