#PAGE_PARAMS# #ADS_HEAD_SCRIPTS# #MICRODATA#

Ultra-Deep Sequencing of Mouse Mitochondrial DNA: Mutational Patterns and Their Origins


Somatic mutations of mtDNA are implicated in the aging process, but there is no universally accepted method for their accurate quantification. We have used ultra-deep sequencing to study genome-wide mtDNA mutation load in the liver of normally- and prematurely-aging mice. Mice that are homozygous for an allele expressing a proof-reading–deficient mtDNA polymerase (mtDNA mutator mice) have 10-times-higher point mutation loads than their wildtype siblings. In addition, the mtDNA mutator mice have increased levels of a truncated linear mtDNA molecule, resulting in decreased sequence coverage in the deleted region. In contrast, circular mtDNA molecules with large deletions occur at extremely low frequencies in mtDNA mutator mice and can therefore not drive the premature aging phenotype. Sequence analysis shows that the main proportion of the mutation load in heterozygous mtDNA mutator mice and their wildtype siblings is inherited from their heterozygous mothers consistent with germline transmission. We found no increase in levels of point mutations or deletions in wildtype C57Bl/6N mice with increasing age, thus questioning the causative role of these changes in aging. In addition, there was no increased frequency of transversion mutations with time in any of the studied genotypes, arguing against oxidative damage as a major cause of mtDNA mutations. Our results from studies of mice thus indicate that most somatic mtDNA mutations occur as replication errors during development and do not result from damage accumulation in adult life.


Vyšlo v časopise: Ultra-Deep Sequencing of Mouse Mitochondrial DNA: Mutational Patterns and Their Origins. PLoS Genet 7(3): e32767. doi:10.1371/journal.pgen.1002028
Kategorie: Research Article
prolekare.web.journal.doi_sk: https://doi.org/10.1371/journal.pgen.1002028

Souhrn

Somatic mutations of mtDNA are implicated in the aging process, but there is no universally accepted method for their accurate quantification. We have used ultra-deep sequencing to study genome-wide mtDNA mutation load in the liver of normally- and prematurely-aging mice. Mice that are homozygous for an allele expressing a proof-reading–deficient mtDNA polymerase (mtDNA mutator mice) have 10-times-higher point mutation loads than their wildtype siblings. In addition, the mtDNA mutator mice have increased levels of a truncated linear mtDNA molecule, resulting in decreased sequence coverage in the deleted region. In contrast, circular mtDNA molecules with large deletions occur at extremely low frequencies in mtDNA mutator mice and can therefore not drive the premature aging phenotype. Sequence analysis shows that the main proportion of the mutation load in heterozygous mtDNA mutator mice and their wildtype siblings is inherited from their heterozygous mothers consistent with germline transmission. We found no increase in levels of point mutations or deletions in wildtype C57Bl/6N mice with increasing age, thus questioning the causative role of these changes in aging. In addition, there was no increased frequency of transversion mutations with time in any of the studied genotypes, arguing against oxidative damage as a major cause of mtDNA mutations. Our results from studies of mice thus indicate that most somatic mtDNA mutations occur as replication errors during development and do not result from damage accumulation in adult life.


Zdroje

1. HarmanD 1972 The biologic clock: the mitochondria? J Am Geriatr Soc 20 145 147

2. MiquelJEconomosACFlemingJJohnsonJEJr 1980 Mitochondrial role in cell aging. Exp Gerontol 15 575 591

3. KrishnanKJGreavesLCReeveAKTurnbullD 2007 The ageing mitochondrial genome. Nucleic Acids Res 35 7399 7405

4. LarssonNG 2010 Somatic mitochondrial DNA mutations in mammalian aging. Annu Rev Biochem 79 683 706

5. CortopassiGAArnheimN 1990 Detection of a specific mitochondrial DNA deletion in tissues of older humans. Nucleic Acids Res 18 6927 6933

6. IkebeSTanakaMOhnoKSatoWHattoriK 1990 Increase of deleted mitochondrial DNA in the striatum in Parkinson's disease and senescence. Biochem Biophys Res Commun 170 1044 1048

7. KatayamaMTanakaMYamamotoHOhbayashiTNimuraY 1991 Deleted mitochondrial DNA in the skeletal muscle of aged individuals. Biochem Int 25 47 56

8. YenTCSuJHKingKLWeiYH 1991 Ageing-associated 5 kb deletion in human liver mitochondrial DNA. Biochem Biophys Res Commun 178 124 131

9. HattoriKTanakaMSugiyamaSObayashiTItoT 1991 Age-dependent increase in deleted mitochondrial DNA in the human heart: possible contributory factor to presbycardia. Am Heart J 121 1735 1742

10. SchwarzeSRLeeCMChungSSRoeckerEBWeindruchR 1995 High levels of mitochondrial DNA deletions in skeletal muscle of old rhesus monkeys. Mech Ageing Dev 83 91 101

11. PikoL 1992 Accumulation of mtDNA defects and changes in mtDNA content in mouse and rat tissues with aging. Ann N Y Acad Sci 663 450 452

12. TrifunovicAHanssonAWredenbergARovioATDufourE 2005 Somatic mtDNA mutations cause aging phenotypes without affecting reactive oxygen species production. Proc Natl Acad Sci U S A 102 17993 17998

13. TrifunovicAWredenbergAFalkenbergMSpelbrinkJNRovioAT 2004 Premature ageing in mice expressing defective mitochondrial DNA polymerase. Nature 429 417 423

14. KujothGCHionaAPughTDSomeyaSPanzerK 2005 Mitochondrial DNA mutations, oxidative stress, and apoptosis in mammalian aging. Science 309 481 484

15. EdgarDShabalinaICamaraYWredenbergACalvarusoMA 2009 Random point mutations with major effects on protein-coding genes are the driving force behind premature aging in mtDNA mutator mice. Cell Metab 10 131 138

16. VermulstMWanagatJKujothGCBielasJHRabinovitchPS 2008 DNA deletions and clonal mutations drive premature aging in mitochondrial mutator mice. Nat Genet 40 392 394

17. VermulstMWanagatJLoebLA 2009 On mitochondria, mutations, and methodology. Cell Metab 10 437

18. EdgarDLarssonNGTrifunovicA 2010 Response: Point Mutations Are Causing Progeroid Phenotypes in the mtDNA Mutator Mouse. Cell Metab 11 93

19. BaileyLJCluettTJReyesAProllaTAPoultonJ 2009 Mice expressing an error-prone DNA polymerase in mitochondria display elevated replication pausing and chromosomal breakage at fragile sites of mitochondrial DNA. Nucleic Acids Res 37 2327 2335

20. KraytsbergYSimonDKTurnbullDMKhrapkoK 2009 Do mtDNA deletions drive premature aging in mtDNA mutator mice? Aging Cell 8 502 506

21. WilliamsSLHuangJEdwardsYJUlloaRHDillonLM 2010 The mtDNA mutation spectrum of the progeroid Polg mutator mouse includes abundant control region multimers. Cell Metab 12 675 682

22. HeYWuJDressmanDCIacobuzio-DonahueCMarkowitzSD 2010 Heteroplasmic mitochondrial DNA mutations in normal and tumour cells. Nature 464 610 614

23. LiMSchonbergASchaeferMSchroederRNasidzeI 2010 Detecting heteroplasmy from high-throughput sequencing of complete human mitochondrial DNA genomes. Am J Hum Genet 87 237 249

24. StewartJBFreyerCElsonJLWredenbergACansuZ 2008 Strong Purifying Selection in Transmission of Mammalian Mitochondrial DNA. PLoS Biol 6 e10 doi:10.1371/journal.pbio.0060010

25. KhrapkoKCollerHAAndrePCLiXCHanekampJS 1997 Mitochondrial mutational spectra in human cells and tissues. Proc Natl Acad Sci U S A 94 13798 13803

26. ZhengWKhrapkoKCollerHAThillyWGCopelandWC 2006 Origins of human mitochondrial point mutations as DNA polymerase gamma-mediated errors. Mutat Res 599 11 20

27. ElliottHRSamuelsDCEdenJAReltonCLChinneryPF 2008 Pathogenic mitochondrial DNA mutations are common in the general population. Am J Hum Genet 83 254 260

28. AmeurAWetterbomAFeukLGyllenstenU 2010 Global and unbiased detection of splice junctions from RNA-seq data. Genome Biol 11 R34

29. RovioAT 2006 DNA Polymerase Gamma Mutaions in Male Infertility and Ageing. Tampere University of Tampere 137

30. VermulstMBielasJHKujothGCLadigesWCRabinovitchPS 2007 Mitochondrial point mutations do not limit the natural lifespan of mice. Nat Genet 39 540 543

31. FalkenbergMLarssonNGGustafssonCM 2007 DNA replication and transcription in mammalian mitochondria. Annu Rev Biochem 76 679 699

32. HoltIJHardingAEMorgan-HughesJA 1988 Deletions of muscle mitochondrial DNA in patients with mitochondrial myopathies. Nature 331 717 719

33. InoueKNakadaKOguraAIsobeKGotoY 2000 Generation of mice with mitochondrial dysfunction by introducing mouse mtDNA carrying a deletion into zygotes. Nat Genet 26 176 181

34. TyynismaaHMjosundKPWanrooijSLappalainenIYlikallioE 2005 Mutant mitochondrial helicase Twinkle causes multiple mtDNA deletions and a late-onset mitochondrial disease in mice. Proc Natl Acad Sci U S A 102 17687 17692

35. NakaseHMoraesCTRizzutoRLombesADiMauroS 1990 Transcription and translation of deleted mitochondrial genomes in Kearns-Sayre syndrome: implications for pathogenesis. Am J Hum Genet 46 418 427

36. ChenHVermulstMWangYEChomynAProllaTA 2010 Mitochondrial fusion is required for mtDNA stability in skeletal muscle and tolerance of mtDNA mutations. Cell 141 280 289

37. KukatATrifunovicA 2009 Somatic mtDNA mutations and aging–facts and fancies. Exp Gerontol 44 101 105

38. Jensen-SeamanMIWildschutteJHSoto-CalderonIDAnthonyNM 2009 A comparative approach shows differences in patterns of numt insertion during hominoid evolution. J Mol Evol 68 688 699

39. Bayona-BafaluyMPAcin-PerezRMullikinJCParkJSMoreno-LoshuertosR 2003 Revisiting the mouse mitochondrial DNA sequence. Nucleic Acids Res 31 5349 5355

Štítky
Genetika Reprodukčná medicína

Článok vyšiel v časopise

PLOS Genetics


2011 Číslo 3
Najčítanejšie tento týždeň
Najčítanejšie v tomto čísle
Kurzy

Zvýšte si kvalifikáciu online z pohodlia domova

Získaná hemofilie - Povědomí o nemoci a její diagnostika
nový kurz

Eozinofilní granulomatóza s polyangiitidou
Autori: doc. MUDr. Martina Doubková, Ph.D.

Všetky kurzy
Prihlásenie
Zabudnuté heslo

Zadajte e-mailovú adresu, s ktorou ste vytvárali účet. Budú Vám na ňu zasielané informácie k nastaveniu nového hesla.

Prihlásenie

Nemáte účet?  Registrujte sa

#ADS_BOTTOM_SCRIPTS#