Knockout of Pseudouridine synthase 1 (PUS1) in mice. [Liver]

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 liver 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（Mitochondrial Myopathy with Lactic acidosis and Sideroblastic Anemia，MLASA）小鼠模型，我们敲除了假尿苷合酶1（Pseudouridine synthase 1，PUS1）的编码基因。该酶可对多种胞质、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-/-小鼠可存活，出生比例符合预期的孟德尔遗传频率，且无形态畸形。Pus1-/-小鼠的胞质及线粒体tRNA中，PUS1信使RNA（mRNA）及特定假尿苷修饰均缺失。该小鼠在14周龄时表现出运动能力下降，并伴随肌肉形态、组织学及生理学特征改变。来自Pus1-/-小鼠的红色腓肠肌，其线粒体数量与体积均减少，且细胞色素C氧化酶活性降低。本实验为双条件双色实验：选取野生型与PUS1纯合突变型小鼠的肝组织样本，每组各设4个生物学重复。