Knockout of Pseudouridine synthase 1 (PUS1) in mice. [M2-Muscle]

In an effort to produce a mouse model of Mitochondrial Myopathy with Lactic acidosis and Sideroblastic Anemia (MLASA), we knocked out the gene for Pseudouridine synthase 1 (PUS1), an enzyme that modifies uridine to pseudouridine in many cytoplasmic and mitochondrial tRNAs, as well as other cellular RNAs. The Pus1-/- mice are viable, are born at the expected Mendelian frequency, and are non-dysmorphic. The PUS1 mRNA and certain pseudouridine modifications are absent in cytoplasmic and mitochondrial tRNAs in the Pus1-/- mice. The Pus1-/- mice display reduce exercise capacity at 14 weeks, with alterations in muscle morphology, histology, and physiology. Red gastrocnemius muscle from Pus1-/- mice shows reduced number and size of mitochondria and reduced Cytochrome C oxidase activity. Two-condition, two-color experiment: Mouse wild type PUS1 and homozygous mutant PUS1 M2-skeletal muscle (white, fast) tissue samples: 4 biological replicates each.为构建伴乳酸酸中毒和铁粒幼细胞性贫血的线粒体肌病（MLASA）小鼠模型，我们敲除了假尿苷合酶1（PUS1）的编码基因——该酶可对众多细胞质与线粒体转运RNA（tRNA）及其他细胞RNA中的尿苷进行假尿苷化修饰。Pus1基因敲除纯合（Pus1-/-）小鼠可正常存活，出生比例符合预期的孟德尔遗传频率，且无形态异常表型。在Pus1-/-小鼠的细胞质与线粒体tRNA中，PUS1信使RNA（mRNA）及特定假尿苷修饰均缺失。Pus1-/-小鼠在14周龄时即出现运动能力下降，并伴随肌肉形态、组织学与生理学特征的改变。取自Pus1-/-小鼠的红色腓肠肌，其线粒体数量与体积均显著减少，细胞色素C氧化酶活性降低。本实验为双条件双色试验：分别选取野生型PUS1与纯合突变型PUS1小鼠的M2型快收缩白色骨骼肌组织样本，每组设置4个生物学重复。