title: Construction of two novel reciprocal conplastic rat strains and characterization of cardiac mitochondria.
abstract: Because of the lack of appropriate animal models, the potentially causal contributions of inherited mitochondrial genomic factors to complex traits are less well studied compared with inherited nuclear genomic factors. We previously detected variations between the mitochondrial DNA (mtDNA) of the Dahl salt-sensitive (S) rat and the spontaneously hypertensive rat (SHR). Specifically, multiple variations were detected in mitochondrial genes coding for subunits of proteins essential for electron transport, in mitochondrial reactive oxygen species production, and within the D-loop region. To evaluate the effects of these mtDNA variations in the absence of the corresponding nuclear genomic factors as confounding variables, novel reciprocal strains of S and SHR were constructed and characterized. When compared with that of the S rat, the heart tissue from the S.SHR(mt) conplastic strain wherein the mtDNA of the S rat was substituted with that of the SHR had a significant increase in mtDNA copy number and decrease in mitochondrial reactive oxygen species production. A corresponding increase in aerobic treadmill running capacity and a significant increase in survival that was not related to changes in blood pressure were observed in the S.SHR(mt) rats compared with the S rat. The reciprocal SHR.S(mt) rats did not differ from the SHR in any phenotype tested, suggesting lower penetrance of the S mtDNA on the nuclear genomic background of the SHR. These novel conplastic strains serve as invaluable tools to further dissect the relationship between heart function, aerobic fitness, cardiovascular disease progression, and mortality.
authors.affiliation: Program in Physiological Genomics, Center for Hypertension and Personalized Medicine, Department of Physiology qaand Pharmacology, University of Toledo College of Medicine and Life Sciences, 3000 Arlington Ave., Toledo, OH 43614-2598, USA.
authors.forename: Sivarajan
authors.initials: S
authors.lastname: Kumarasamy
authors.forename: Kathirvel
authors.initials: K
authors.lastname: Gopalakrishnan
authors.forename: Shakila
authors.initials: S
authors.lastname: Abdul-Majeed
authors.forename: Rod
authors.initials: R
authors.lastname: Partow-Navid
authors.forename: Phyllis
authors.initials: P
authors.lastname: Farms
authors.forename: Bina
authors.initials: B
authors.lastname: Joe
mesh_terms: D000818:Animals; D001794:Blood Pressure / Q000235:genetics; D001835:Body Weight / Q000235:genetics; D004272:DNA, Mitochondrial / Q000235:genetics*; D004734:Energy Metabolism / Q000235:genetics; D018628:Gene Dosage; D015971:Gene Expression Regulation, Enzymologic; D005838:Genotype; D006824:Hybridization, Genetic; D008136:Longevity / Q000235:genetics; D008929:Mitochondria, Heart / Q000201:enzymology / Q000378:metabolism*; D008933:Mitochondrial Swelling / Q000235:genetics; D063269:Mitochondrial Turnover / Q000235:genetics; D018384:Oxidative Stress / Q000235:genetics; D019683:Penetrance; D010641:Phenotype; D051381:Rats; D020303:Rats, Inbred Dahl / Q000235:genetics*; D011918:Rats, Inbred SHR / Q000235:genetics*; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D004272:DNA, Mitochondrial; D017382:Reactive Oxygen Species