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Cosegregation of novel mitochondrial 16S rRNA gene mutations with the age-associated T414G variant in human cybrids.

Seibel P, Di Nunno C, Kukat C, Schäfer I, Del Bo R, Bordoni A, Comi GP, Schön A, Capuano F, Latorre D, Villani G - Nucleic Acids Res. (2008)

Bottom Line: In the present work, we have analyzed the bioenergetic properties associated with the age-related T414G mutation of the mtDNA control region in transmitochondrial cybrids.The results show that the T414G mutation does not cause per se any detectable bioenergetic change.The results are discussed in the more general context of the complex heterogeneity and the dramatic instability of the mitochondrial genome during cell culture of transmitochondrial cybrids.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular Cell Therapy, Center for Biotechnology and Biomedicine, Universität Leipzig, Deutscher Platz 5, 04103 Leipzig, Germany. peter.seibel@bbz.uni-leipzig.de

ABSTRACT
Ever increasing evidence has been provided on the accumulation of mutations in the mitochondrial DNA (mtDNA) during the aging process. However, the lack of direct functional consequences of the mutant mtDNA load on the mitochondria-dependent cell metabolism has raised many questions on the physiological importance of the age-related mtDNA variations. In the present work, we have analyzed the bioenergetic properties associated with the age-related T414G mutation of the mtDNA control region in transmitochondrial cybrids. The results show that the T414G mutation does not cause per se any detectable bioenergetic change. Moreover, three mtDNA mutations clustered in the 16S ribosomal RNA gene cosegregated together with the T414G in the same cybrid cell line. Two of them, namely T1843C and A1940G, are novel and associate with a negative bioenergetic phenotype. The results are discussed in the more general context of the complex heterogeneity and the dramatic instability of the mitochondrial genome during cell culture of transmitochondrial cybrids.

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Sequence analyses of the mitochondrial 16S rRNA genes. Displayed are the electropherograms related to the 1843, 1940 and 2623 positions in the 16S rRNA genes of the AL4.8 and AL4.3 cells. The shaded areas highlight the homoplasmic and heteroplasmic peaks of wild-type and mutated mtDNAs, respectively.
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Figure 1: Sequence analyses of the mitochondrial 16S rRNA genes. Displayed are the electropherograms related to the 1843, 1940 and 2623 positions in the 16S rRNA genes of the AL4.8 and AL4.3 cells. The shaded areas highlight the homoplasmic and heteroplasmic peaks of wild-type and mutated mtDNAs, respectively.

Mentions: Surprisingly, the AL4.3 cells displayed three additional heteroplasmic mutations all clustered within the 16S rRNA gene, namely T1843C, A1940G and A2623G (Figure 1). These mutations were neither detectable in the AL4.8 cell line (Figure 1), the AL4.5 and the AL4.27 cell line, nor in the original DNA extract of the donor fibroblasts (data not shown). Interestingly, the A2623G mutation cosegregated in homoplasmic form together with the T414G mutation in the above mentioned cybrid (AC1.2) deriving from a different mitochondrial donor. Also, in this case, the bioenergetic competence of the AC1.2 cell line excluded a direct impact of the A2623G mutation on the mitochondrial functionality.Figure 1.


Cosegregation of novel mitochondrial 16S rRNA gene mutations with the age-associated T414G variant in human cybrids.

Seibel P, Di Nunno C, Kukat C, Schäfer I, Del Bo R, Bordoni A, Comi GP, Schön A, Capuano F, Latorre D, Villani G - Nucleic Acids Res. (2008)

Sequence analyses of the mitochondrial 16S rRNA genes. Displayed are the electropherograms related to the 1843, 1940 and 2623 positions in the 16S rRNA genes of the AL4.8 and AL4.3 cells. The shaded areas highlight the homoplasmic and heteroplasmic peaks of wild-type and mutated mtDNAs, respectively.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2566888&req=5

Figure 1: Sequence analyses of the mitochondrial 16S rRNA genes. Displayed are the electropherograms related to the 1843, 1940 and 2623 positions in the 16S rRNA genes of the AL4.8 and AL4.3 cells. The shaded areas highlight the homoplasmic and heteroplasmic peaks of wild-type and mutated mtDNAs, respectively.
Mentions: Surprisingly, the AL4.3 cells displayed three additional heteroplasmic mutations all clustered within the 16S rRNA gene, namely T1843C, A1940G and A2623G (Figure 1). These mutations were neither detectable in the AL4.8 cell line (Figure 1), the AL4.5 and the AL4.27 cell line, nor in the original DNA extract of the donor fibroblasts (data not shown). Interestingly, the A2623G mutation cosegregated in homoplasmic form together with the T414G mutation in the above mentioned cybrid (AC1.2) deriving from a different mitochondrial donor. Also, in this case, the bioenergetic competence of the AC1.2 cell line excluded a direct impact of the A2623G mutation on the mitochondrial functionality.Figure 1.

Bottom Line: In the present work, we have analyzed the bioenergetic properties associated with the age-related T414G mutation of the mtDNA control region in transmitochondrial cybrids.The results show that the T414G mutation does not cause per se any detectable bioenergetic change.The results are discussed in the more general context of the complex heterogeneity and the dramatic instability of the mitochondrial genome during cell culture of transmitochondrial cybrids.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular Cell Therapy, Center for Biotechnology and Biomedicine, Universität Leipzig, Deutscher Platz 5, 04103 Leipzig, Germany. peter.seibel@bbz.uni-leipzig.de

ABSTRACT
Ever increasing evidence has been provided on the accumulation of mutations in the mitochondrial DNA (mtDNA) during the aging process. However, the lack of direct functional consequences of the mutant mtDNA load on the mitochondria-dependent cell metabolism has raised many questions on the physiological importance of the age-related mtDNA variations. In the present work, we have analyzed the bioenergetic properties associated with the age-related T414G mutation of the mtDNA control region in transmitochondrial cybrids. The results show that the T414G mutation does not cause per se any detectable bioenergetic change. Moreover, three mtDNA mutations clustered in the 16S ribosomal RNA gene cosegregated together with the T414G in the same cybrid cell line. Two of them, namely T1843C and A1940G, are novel and associate with a negative bioenergetic phenotype. The results are discussed in the more general context of the complex heterogeneity and the dramatic instability of the mitochondrial genome during cell culture of transmitochondrial cybrids.

Show MeSH