Screen for abnormal mitochondrial phenotypes in mouse ES cells identifies model for Succinyl-CoA Ligase deficiency and mtDNA depletion
Year: 2013
Type: article
Abstract: Mutations in subunits of succinyl-CoA synthetase/ligase (SCS), a component of the citric acid cycle, are associated with mitochondrial encephalomyopathy, elevation of methylmalonic acid (MMA), and mitochondrial DNA (mtDNA) depletion. A FACS-based retroviral-mediated gene trap mutagenesis screen in mouse embryonic stem (ES) cells for abnormal mitochondrial phenotypes identified a gene trap allele of Sucla2 (Sucla2(SAβgeo)), which was used to generate transgenic mice. Sucla2 encodes the ADP-specific β-subunit isoform of SCS. Sucla2(SAβgeo) homozygotes exhibited recessive lethality, with most mutants dying late in gestation (e18.5). Mutant placenta and embryonic (e17.5) brain, heart and muscle showed varying degrees of mtDNA depletion (20-60%). However, there was no mtDNA depletion in mutant liver, where the gene is not normally expressed. Elevated levels of MMA were observed in embryonic brain. SCS-deficient mouse embryonic fibroblasts (MEFs) demonstrated a 50% reduction in mtDNA content compared with wild-type MEFs. The mtDNA depletion resulted in reduced steady state levels of mtDNA encoded proteins and multiple respiratory chain deficiencies. mtDNA content could be restored by reintroduction of Sucla2. This mouse model of SCS deficiency and mtDNA depletion promises to provide insights into the pathogenesis of mitochondrial diseases with mtDNA depletion and into the biology of mtDNA maintenance. In addition, this report demonstrates the power of a genetic screen that combines gene trap mutagenesis and FACS analysis in mouse ES cells to identify mitochondrial phenotypes and to develop animal models of mitochondrial dysfunction.
Source: Disease Models & Mechanisms
DOI: 10.1242/dmm.013466
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: gold
Estimated APC paid: $3,750
Funders: National Heart, Lung, and Blood Institute, National Cancer Institute, National Institute of General Medical Sciences, National Institute of Allergy and Infectious Diseases, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Center for Research Resources, Eunice Kennedy Shriver National Institute of Child Health and Human Development
Awards: Baylor-UT Houston Center for AIDS Research, BD Biosciences Special Order LSRII, A novel recessive genetic screen for mitochondrial phenotypes in mammalian cells, Baylor Intellectual and Developmental Disabilities Research Center, Genetic Screens for Mitochondrial Phenotypes in ES Cells, Succinyl-COA Synthetase Deficiency: A Model to Study Mitochondrial DNA (MTDNA) De, Baylor College of Medicine Cancer Center - Cancer Center Support Grant
OpenAlex ID: W2133351820