Human Molecular Genetics Advance Access originally published online on May 11, 2005
Human Molecular Genetics 2005 14(13):1775-1783; doi:10.1093/hmg/ddi184
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Mitochondrial DNA polymerase gamma is essential for mammalian embryogenesis
Department of Medical Nutrition and Department of Biosciences at Novum, Karolinska Institute, Stockholm, Sweden
* To whom correspondence should be addressed. Tel: +46 858583726; Fax: +46 87795383; Email: aleksandra.trifunovic{at}mednut.ki.se
Received April 13, 2005; Accepted May 4, 2005
Mitochondrial DNA (mtDNA) polymerase gamma (Polg) is a heterodimeric enzyme containing a Pol I-like catalytic core (PolgA) and an accessory subunit. Mutations in POLGA, affecting the stability of mtDNA, have been identified in several human pathologies such as progressive external ophthalmoplegia and Alpers' syndrome. Extensive literature shows mitochondrial toxicity effects nucleoside analogue reverse transcriptase inhibitors used in the treatment of HIV and chronic hepatitis B as a consequence of an inhibitory effect on Polg. We have previously shown that mice with an error-prone version of PolgA accumulate higher levels of somatic mtDNA mutations resulting in a premature aging phenotype. In the present paper, we demonstrate PolgA deficiency in mouse embryos causes an early developmental arrest between embryonic days 7.5 and 8.5 associated with severe mtDNA depletion. Heterozygous knockout mice have half the wild-type levels of PolgA transcripts and a slight reduction in mtDNA levels but develop normally. Surprisingly, amounts of PolgA transcripts in heterozygous knockout mice are increased in response to artificially elevated mtDNA copy number, revealing a possible regulatory link between mtDNA maintenance and PolgA expression. Our results show that Polg indeed is the only DNA polymerase capable of maintaining mtDNA in mammalian mitochondria. In addition, presence of Polg is absolutely essential for the organogenesis during mammalian embryonic development.
![]()
CiteULike
Connotea
Del.icio.us What's this?
This article has been cited by other articles:
![]() |
M. Di Re, H. Sembongi, J. He, A. Reyes, T. Yasukawa, P. Martinsson, L. J. Bailey, S. Goffart, J. D. Boyd-Kirkup, T. S. Wong, et al. The accessory subunit of mitochondrial DNA polymerase {gamma} determines the DNA content of mitochondrial nucleoids in human cultured cells Nucleic Acids Res., September 1, 2009; 37(17): 5701 - 5713. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. N. Dimitrov, R. B. Brem, L. Kruglyak, and D. E. Gottschling Polymorphisms in Multiple Genes Contribute to the Spontaneous Mitochondrial Genome Instability of Saccharomyces cerevisiae S288C Strains Genetics, September 1, 2009; 183(1): 365 - 383. [Abstract] [Full Text] [PDF] |
||||
![]() |
I. Bratic, J. Hench, J. Henriksson, A. Antebi, T. R Burglin, and A. Trifunovic Mitochondrial DNA level, but not active replicase, is essential for Caenorhabditis elegans development Nucleic Acids Res., April 1, 2009; 37(6): 1817 - 1828. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. H. Pua, J. Guo, M. Komatsu, and Y.-W. He Autophagy Is Essential for Mitochondrial Clearance in Mature T Lymphocytes J. Immunol., April 1, 2009; 182(7): 4046 - 4055. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. E Lloyd, R. Romar, C. Matas, A. Gutierrez-Adan, W. V Holt, and P. Coy Effects of oviductal fluid on the development, quality, and gene expression of porcine blastocysts produced in vitro Reproduction, April 1, 2009; 137(4): 679 - 687. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. C. Scarpulla Transcriptional Paradigms in Mammalian Mitochondrial Biogenesis and Function Physiol Rev, April 1, 2008; 88(2): 611 - 638. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. M. Facucho-Oliveira, J. Alderson, E. C. Spikings, S. Egginton, and J. C. St. John Mitochondrial DNA replication during differentiation of murine embryonic stem cells J. Cell Sci., November 15, 2007; 120(22): 4025 - 4034. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Amaral, J. Ramalho-Santos, and J. C. St John The expression of polymerase gamma and mitochondrial transcription factor A and the regulation of mitochondrial DNA content in mature human sperm Hum. Reprod., June 1, 2007; 22(6): 1585 - 1596. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. J. Lindhurst, G. Fiermonte, S. Song, E. Struys, F. De Leonardis, P. L. Schwartzberg, A. Chen, A. Castegna, N. Verhoeven, C. K. Mathews, et al. Knockout of Slc25a19 causes mitochondrial thiamine pyrophosphate depletion, embryonic lethality, CNS malformations, and anemia PNAS, October 24, 2006; 103(43): 15927 - 15932. [Abstract] [Full Text] [PDF] |
||||
![]() |
E.C. Spikings, J. Alderson, and J.C.St. John Transmission of mitochondrial DNA following assisted reproduction and nuclear transfer Hum. Reprod. Update, July 1, 2006; 12(4): 401 - 415. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. H El Shourbagy, E. C Spikings, M. Freitas, and J. C St John Mitochondria directly influence fertilisation outcome in the pig Reproduction, February 1, 2006; 131(2): 233 - 245. [Abstract] [Full Text] [PDF] |
||||








