Gene Targeting of Mouse Tardbp Negatively Affects Masp2 Expression
Gene Targeting of Mouse Tardbp Negatively Affects Masp2 Expression
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DOI：
10.1371/journal.pone.0095373
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发表时间：
2014-04-16
期刊：
影响因子：
3.7
通讯作者：
Robertson, Janice
中科院分区：
文献类型：
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作者：
Dib, Samar;Xiao, Shangxi;Robertson, Janice
肌萎缩侧索硬化症 (ALS) 是一种毁灭性的成人发病神经退行性疾病，影响上运动神经元和下运动神经元。由 TARDBP 基因编码的 TDP-43 被鉴定为家族性和散发性 ALS 中运动神经元细胞质内含物的组成部分，并已成为该疾病的病理特征。 TDP-43 是一种参与 RNA 代谢的核蛋白，但在 ALS 中，TDP-43 错误定位到受影响运动神经元的细胞质，这表明疾病可能是由 TDP-43 功能丧失引起的。为了研究这一假设，我们尝试使用经典的 Cre-loxP 技术产生 Tardbp 基因的小鼠条件敲除。尽管成功生成了目标等位基因的杂合子小鼠，但我们无法获得纯合子。在这里，我们表明，虽然靶向载体经过专门设计，不与 Tardbp 相邻基因重叠，但同源重组事件影响了下游基因 Masp2 的表达。这可以解释为什么无法获得具有靶向 Tardbp 的纯合子小鼠。
Amyotrophic Lateral Sclerosis (ALS) is a devastating adult onset neurodegenerative disease affecting both upper and lower motor neurons. TDP-43, encoded by the TARDBP gene, was identified as a component of motor neuron cytoplasmic inclusions in both familial and sporadic ALS and has become a pathological signature of the disease. TDP-43 is a nuclear protein involved in RNA metabolism, however in ALS, TDP-43 is mislocalized to the cytoplasm of affected motor neurons, suggesting that disease might be caused by TDP-43 loss of function. To investigate this hypothesis, we attempted to generate a mouse conditional knockout of the Tardbp gene using the classical Cre-loxP technology. Even though heterozygote mice for the targeted allele were successfully generated, we were unable to obtain homozygotes. Here we show that although the targeting vector was specifically designed to not overlap with Tardbp adjacent genes, the homologous recombination event affected the expression of a downstream gene, Masp2. This may explain the inability to obtain homozygote mice with targeted Tardbp.