Generation of trans-mitochondrial mice carrying homoplasmic mtDNAs with a missense mutation in a structural gene using ES cells

Abstract

Generation of various kinds of trans-mitochondrial mice, mito-mice, each carrying mtDNAs with a different pathogenic mutation, is required for precise investigation of the pathogenesis of mitochondrial diseases. This study used two respiration-deficient mouse cell lines as donors of mtDNAs with possible pathogenic mutations. One cell line expressed 45-50% respiratory activity due to mouse mtDNAs with a T6589C missense mutation in the COI gene (T6589C mtDNA) and the other expressed 40% respiratory activity due to rat (Rattus norvegicus) mtDNAs in mouse cells. By cytoplasmic transfer of these mtDNAs to mouse ES cells, we isolated respiration-deficient ES cells. We obtained chimeric mice and generated their F(6) progeny carrying mouse T6589C mtDNAs by its female germ line transmission. They were respiration-deficient and thus could be used as models of mitochondrial diseases caused by point mutations in mtDNA structural genes. However, chimeric mice and mito-mice carrying rat mtDNAs were not obtained, suggesting that significant respiration defects or some deficits induced by rat mtDNAs in mouse ES cells prevented their differentiation to generate mice carrying rat mtDNAs.

Specific mitochondrial DNA mutation in mice regulates diabetes and lymphoma development

“…Our previous study (19) also showed that young mito-miceND6 M (3-mo-old males) have slight lactic acidosis, a common phenotype in humans with mitochondrial diseases (1, 2) and in mito-mice with other pathogenic mtDNA mutations (20)(21)(22). Using aged mitomiceND6 M (21-mo-old males), this study reexamined blood lactate levels.…”

“…Using aged mitomiceND6 M (21-mo-old males), this study reexamined blood lactate levels. We also used mito-miceCOI M , which we had generated previously (21), as positive controls with lactic acidosis due to respiration complex IV defects caused by a pathogenic T6589C mtDNA mutation in the COI gene. Unlike B6 mice, both aged mito-miceND6 M and age-matched mito-miceCOI M (21-mo-old males) had slight lactic acidosis in the peripheral blood (Fig.…”

“…As controls, we used age-matched B6 mice with normal mtDNA and mitomiceCOI M mice with pathogenic T6589C mtDNA (21), which induces respiration defects and the resultant lactate overproduction but not ROS overproduction (17). All of the mice used in this study shared the B6 nuclear DNA background, thus excluding the possible involvement of nuclear genetic variations in the phenotypes exclusively developed in mito-miceND6 M .…”

Nuclear but Not Mitochondrial DNA Involvement in Respiratory Complex I Defects Found in Senescence-Accelerated Mouse Strain, SAMP8

“…We reported previously that mtDNA-induced respiration defects expressed in cultivated P29 cybrids can be restored when the pathogenic mtDNAs are transferred into mouse tissues [7,23]. This restoration is presumed to be a consequence of some compensatory function that is exclusively present in the tissues but not in cultivated P29 cybrids.…”

“…This restoration is presumed to be a consequence of some compensatory function that is exclusively present in the tissues but not in cultivated P29 cybrids. For example, P29mtA11 and P29mt6589 cybrids, which possess a G13997A mutation in the mtNd6 gene and a T6589C mutation in the mt-Co1 gene, show approximately 20% complex I [3] and 40% complex IV activity [7], respectively, when compared with P29mtB6 cybrids. In contrast, tissues from the transmitochondrial mice, mito-mice13997 and mito-mice6589, which in turn possess G13997A and T6589C mtDNA introduced from the P29mtA11 and P29mt6589 cybrids, show approximately 70% complex I [23] and 70% com- plex IV activity [7], respectively, when compared with age-matched B6 mice.…”