Mouse Models of Mitochondrial Encephalomyopathies

描述（由申请人提供）：氧化磷酸化（OXPHOS）缺陷与各种神经肌肉退行性过程相关。我们建议利用目前的方法，允许操作胚胎干细胞中的核基因，并产生和表征的小鼠模型与核编码的OXPHOS基因的条件突变。该提议将测试的一般假设和问题是：i）敲除因子对OXPHOS组装和功能的具体作用是什么？ii）不同的细胞群是否更容易受到特定OXPHOS复合物缺陷的影响？iii）肌肉或神经中特定呼吸链复合物的缺陷是否会导致不同的肌肉或神经退行性表型？iv）这些表型是否与不同水平的氧化损伤或蛋白质聚集相关？具体而言，我们将开发敲入小鼠的三个呼吸复合体基因，其中一个进化上保守的外显子两侧是IoxP位点。将操作以下基因：NDUFS1基因（复合物I）、铁硫蛋白（复合物III）和COX 10，一种血红素O法尼基转移酶（血红素a产生和复合物IV活性所需）。敲入动物将与表达由CNS和骨骼肌启动子驱动的Cre重组酶的小鼠杂交。我们希望这些研究提供证据表明，在OXPHOS的特定缺陷可以表现为不同的表型改变。

DESCRIPTION (provided by applicant): Defects in oxidative phosphorylation (OXPHOS) have been associated with various neuromuscular degenerative processes. We propose to take advantage of current methodology that allows the manipulation of nuclear genes in embryonic stem cells and generate and characterize of mouse models with conditional mutations in nuclear-coded OXPHOS genes. The general hypotheses and questions this proposal will test are: i) What are the specific role of the knocked out factors on OXPHOS assembly and function? ii) Are different cell populations more susceptible to defects in specific OXPHOS complexes? iii) Do defects in specific respiratory chain complexes in muscle or nerves lead to different muscular or neurodegenerative phenotypes? iv) Are these phenotypes associated with different levels of oxidative damage or protein aggregation? Specifically, we will develop knock in mice for three respiratory complex genes in which an evolutionarily conserved exon is flanked by IoxP sites. The following genes will be manipulated: the NDUFS1 gene (complex I), Iron-Sulfur Protein (complex III) and COX10, a protoheme O farnesyl-transferase (required for heme a production and complex IV activity). The knockin animals will be crossed with mice expressing Cre-recombinase driven by CNS and skeletal muscle promoters. We expect these studies to provide evidence that specific defects in the OXPHOS can manifest as distinct phenotypic alterations.