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Yang YP, Chang YL, Lai YH, Tsai PH, Hsiao YJ, Nguyen LH, Lim XZ, Weng CC, Ko YL, Yang CH, Hwang DK, Chen SJ, Chiou SH, Chiou GY, Wang AG, Chien Y. Retinal Circular RNA hsa_circ_0087207 Expression Promotes Apoptotic Cell Death in Induced Pluripotent Stem Cell-Derived Leber’s Hereditary Optic Neuropathy-like Models. Biomedicines 2022; 10:biomedicines10040788. [PMID: 35453537 PMCID: PMC9027941 DOI: 10.3390/biomedicines10040788] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2022] [Revised: 03/22/2022] [Accepted: 03/24/2022] [Indexed: 02/01/2023] Open
Abstract
Backgrounds: Leber’s hereditary optic neuropathy (LHON) is known as an inherited retinal disorder characterized by the bilateral central vision loss and degeneration of retinal ganglion cells (RGCs). Unaffected LHON carriers are generally asymptomatic, suggesting that certain factors may contribute to the disease manifestations between carriers and patients who carry the same mutated genotypes. Methods: We first aimed to establish the iPSC-differentiated RGCs from the normal healthy subject, the carrier, and the LHON patient and then compared the differential expression profile of circular RNAs (CircRNAs) among RGCs from these donors in vitro. We further overexpressed or knocked down the most upregulated circRNA to examine whether this circRNA contributes to the distinct phenotypic manifestations between the carrier- and patient-derived RGCs. Results: iPSCs were generated from the peripheral blood cells from the healthy subject, the carrier, and the LHON patient and successfully differentiated into RGCs. These RGCs carried equivalent intracellular reactive oxygen species, but only LHON-patient iPSC-derived RGCs exhibited remarkable apoptosis. Next-generation sequencing and quantitative real-time PCR revealed the circRNA hsa_circ_0087207 as the most upregulated circRNA in LHON-patient iPSC-derived RGCs. Overexpression of hsa_circ_0087207 increased the apoptosis in carrier iPSC-derived RGCs, while knockdown of hsa_circ_0087207 attenuated the apoptosis in LHON-patient iPSC-derived RGCs. Predicted by bioinformatics approaches, hsa_circ_0087207 acts as the sponge of miR-665 to induce the expression of a variety of apoptosis-related genes in LHON patient iPSC-derived RGCs. Conclusions: Our data indicated that hsa_circ_0087207 upregulation distinguishes the disease phenotype manifestations between iPSC-derived RGCs generated from the LHON patient and carrier. Targeting the hsa_circ_0087207/miR-665 axis might hold therapeutic promises for the treatment of LHON.
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Affiliation(s)
- Yi-Ping Yang
- Department of Medical Research, Taipei Veteran General Hospital, Taipei 11217, Taiwan; (Y.-P.Y.); (Y.-H.L.); (P.-H.T.); (Y.-J.H.); (L.H.N.); (X.-Z.L.); (Y.-L.K.); (S.-H.C.)
- Institute of Food Safety and Health Risk Assessment, School of Pharmaceutical Sciences, National Yang Ming Chiao Tung University, Taipei 11217, Taiwan
- School of Medicine, National Yang-Ming Chiao Tung University, Taipei 11217, Taiwan; (D.-K.H.); (S.-J.C.); (A.-G.W.)
| | - Yuh-Lih Chang
- Department of Pharmacy, Taipei Veterans General Hospital, Taipei 11217, Taiwan;
- Department of Pharmacy, National Yang Ming Chiao Tung University, Taipei 11217, Taiwan
| | - Yun-Hsien Lai
- Department of Medical Research, Taipei Veteran General Hospital, Taipei 11217, Taiwan; (Y.-P.Y.); (Y.-H.L.); (P.-H.T.); (Y.-J.H.); (L.H.N.); (X.-Z.L.); (Y.-L.K.); (S.-H.C.)
- Institute of Pharmacology, College of Medicine, National Yang Ming Chiao Tung University, Taipei 11217, Taiwan
| | - Ping-Hsing Tsai
- Department of Medical Research, Taipei Veteran General Hospital, Taipei 11217, Taiwan; (Y.-P.Y.); (Y.-H.L.); (P.-H.T.); (Y.-J.H.); (L.H.N.); (X.-Z.L.); (Y.-L.K.); (S.-H.C.)
- Institute of Pharmacology, College of Medicine, National Yang Ming Chiao Tung University, Taipei 11217, Taiwan
| | - Yu-Jer Hsiao
- Department of Medical Research, Taipei Veteran General Hospital, Taipei 11217, Taiwan; (Y.-P.Y.); (Y.-H.L.); (P.-H.T.); (Y.-J.H.); (L.H.N.); (X.-Z.L.); (Y.-L.K.); (S.-H.C.)
- School of Medicine, National Yang-Ming Chiao Tung University, Taipei 11217, Taiwan; (D.-K.H.); (S.-J.C.); (A.-G.W.)
| | - Long Hoang Nguyen
- Department of Medical Research, Taipei Veteran General Hospital, Taipei 11217, Taiwan; (Y.-P.Y.); (Y.-H.L.); (P.-H.T.); (Y.-J.H.); (L.H.N.); (X.-Z.L.); (Y.-L.K.); (S.-H.C.)
- Institute of Pharmacology, College of Medicine, National Yang Ming Chiao Tung University, Taipei 11217, Taiwan
- Department of Basic Medical Sciences, Hanoi University of Pharmacy, Hanoi 100000, Vietnam
| | - Xue-Zhen Lim
- Department of Medical Research, Taipei Veteran General Hospital, Taipei 11217, Taiwan; (Y.-P.Y.); (Y.-H.L.); (P.-H.T.); (Y.-J.H.); (L.H.N.); (X.-Z.L.); (Y.-L.K.); (S.-H.C.)
- Institute of Pharmacology, College of Medicine, National Yang Ming Chiao Tung University, Taipei 11217, Taiwan
| | - Chang-Chi Weng
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei 11217, Taiwan;
| | - Yu-Ling Ko
- Department of Medical Research, Taipei Veteran General Hospital, Taipei 11217, Taiwan; (Y.-P.Y.); (Y.-H.L.); (P.-H.T.); (Y.-J.H.); (L.H.N.); (X.-Z.L.); (Y.-L.K.); (S.-H.C.)
| | - Chang-Hao Yang
- Department of Ophthalmology, National Taiwan University Hospital, Taipei 10002, Taiwan;
- Department of Ophthalmology, College of Medicine, National Taiwan University, Taipei 11217, Taiwan
| | - De-Kuang Hwang
- School of Medicine, National Yang-Ming Chiao Tung University, Taipei 11217, Taiwan; (D.-K.H.); (S.-J.C.); (A.-G.W.)
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei 11217, Taiwan;
| | - Shih-Jen Chen
- School of Medicine, National Yang-Ming Chiao Tung University, Taipei 11217, Taiwan; (D.-K.H.); (S.-J.C.); (A.-G.W.)
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei 11217, Taiwan;
| | - Shih-Hwa Chiou
- Department of Medical Research, Taipei Veteran General Hospital, Taipei 11217, Taiwan; (Y.-P.Y.); (Y.-H.L.); (P.-H.T.); (Y.-J.H.); (L.H.N.); (X.-Z.L.); (Y.-L.K.); (S.-H.C.)
- School of Medicine, National Yang-Ming Chiao Tung University, Taipei 11217, Taiwan; (D.-K.H.); (S.-J.C.); (A.-G.W.)
- Institute of Pharmacology, College of Medicine, National Yang Ming Chiao Tung University, Taipei 11217, Taiwan
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei 11217, Taiwan;
- Genomic Research Center, Academia Sinica, Taipei 11217, Taiwan
| | - Guang-Yuh Chiou
- Department of Biological Science and Technology, College of Biological Science and Technology, National Yang Ming Chiao Tung University, Hsinchu 300093, Taiwan
- Correspondence: (G.-Y.C.); (Y.C.)
| | - An-Guor Wang
- School of Medicine, National Yang-Ming Chiao Tung University, Taipei 11217, Taiwan; (D.-K.H.); (S.-J.C.); (A.-G.W.)
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei 11217, Taiwan;
| | - Yueh Chien
- Department of Medical Research, Taipei Veteran General Hospital, Taipei 11217, Taiwan; (Y.-P.Y.); (Y.-H.L.); (P.-H.T.); (Y.-J.H.); (L.H.N.); (X.-Z.L.); (Y.-L.K.); (S.-H.C.)
- School of Medicine, National Yang-Ming Chiao Tung University, Taipei 11217, Taiwan; (D.-K.H.); (S.-J.C.); (A.-G.W.)
- Correspondence: (G.-Y.C.); (Y.C.)
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Human germline nuclear transfer to overcome mitochondrial disease and failed fertilization after ICSI. J Assist Reprod Genet 2022; 39:609-618. [PMID: 35064435 PMCID: PMC8995215 DOI: 10.1007/s10815-022-02401-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 01/15/2022] [Indexed: 10/19/2022] Open
Abstract
PURPOSE Providing additional insights on the efficacy of human nuclear transfer (NT). Here, and earlier, NT has been applied to minimize transmission risk of mitochondrial DNA (mtDNA) diseases. NT has also been proposed for treating infertility, but it is still unclear which infertility indications would benefit. In this work, we therefore additionally assess the applicability of NT to overcome failed fertilization. METHODS Patient 1 carries a homoplasmic mtDNA mutation (m.11778G > A). Seventeen metaphase II (MII) oocytes underwent pre-implantation genetic testing (PGT), while five MII oocytes were used for spindle transfer (ST), and one in vitro matured (IVM) metaphase I oocyte underwent early pronuclear transfer (ePNT). Patients 2-3 experienced multiple failed intracytoplasmic sperm injection (ICSI) and ICSI-assisted oocyte activation (AOA) cycles. For these patients, the obtained MII oocytes underwent an additional ICSI-AOA cycle, while the IVM oocytes were subjected to ST. RESULTS For patient 1, PGT-M confirmed mutation loads close to 100%. All ST-reconstructed oocytes fertilized and cleaved, of which one progressed to the blastocyst stage. The reconstructed ePNT-zygote reached the morula stage. These samples showed an average mtDNA carry-over rate of 2.9% ± 0.8%, confirming the feasibility of NT to reduce mtDNA transmission. For patient 2-3 displaying fertilization failure, ST resulted in, respectively, 4/5 and 6/6 fertilized oocytes, providing evidence, for the first time, that NT can enable successful fertilization in this patient population. CONCLUSION Our study showcases the repertoire of disorders for which NT can be beneficial, to overcome either mitochondrial disease transmission or failed fertilization after ICSI-AOA.
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Heteroplasmy Detection of Mitochondrial DNA A3243G Mutation Using Quantitative Real-Time PCR Assay Based on TaqMan-MGB Probes. BIOMED RESEARCH INTERNATIONAL 2018; 2018:1286480. [PMID: 30539000 PMCID: PMC6260548 DOI: 10.1155/2018/1286480] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Revised: 07/16/2018] [Accepted: 09/18/2018] [Indexed: 12/22/2022]
Abstract
A point mutation of mitochondrial DNA (mtDNA) at nucleotide position 3243 A to G (mt.3243A>G) is involved in many common diseases, including maternally inherited diabetes and deafness (MIDD) and mitochondrial encephalomyopathy, lactic acidosis with stroke-like episodes (MELAS). However, the mutant level of mt.3243A>G varies both among individuals and in different organs, tissues, and even cells of single individuals. For detection of this mutation, current methods have limited universality and sensitivity and may be not adequate for a routine clinical test. Here, we develop and evaluate a rapid TaqMan-MGB quantitative real-time PCR (qPCR) method for detecting and quantifying the heteroplasmy level of mt.3243A>G in single-tube analysis. With our method, the sensitivity of detection was as low as 0.1%, but the accuracy of quantification was reliable, down to 4%. All positives could be correctly identified, and the heteroplasmy levels determined by qPCR correlated well with the results from restriction fragment length polymorphism (RFLP) and pyrosequencing assays (r = 0.921~0.973 and 0.972~0.984). In addition, we demonstrated that the urinary sediments, leukocytes, or hair follicles might be ideal templates to detect and quantify the heteroplasmy of mt.3243A>G mutation; however, they should be optimized or retreated for further accurate quantification. Our study should allow rapid and high throughput diagnostic testing and can potentially be used to clarify the association between clinical phenotype and pathogenic mitochondrial mutations derived from various tissues.
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Emperador S, Vidal M, Hernández-Ainsa C, Ruiz-Ruiz C, Woods D, Morales-Becerra A, Arruga J, Artuch R, López-Gallardo E, Bayona-Bafaluy MP, Montoya J, Ruiz-Pesini E. The Decrease in Mitochondrial DNA Mutation Load Parallels Visual Recovery in a Leber Hereditary Optic Neuropathy Patient. Front Neurosci 2018; 12:61. [PMID: 29479304 PMCID: PMC5811516 DOI: 10.3389/fnins.2018.00061] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Accepted: 01/24/2018] [Indexed: 11/13/2022] Open
Abstract
The onset of Leber hereditary optic neuropathy is relatively rare in childhood and, interestingly, the rate of spontaneous visual recovery is very high in this group of patients. Here, we report a child harboring a rare pathological mitochondrial DNA mutation, present in heteroplasmy, associated with the disease. A patient follow-up showed a rapid recovery of the vision accompanied by a decrease of the percentage of mutated mtDNA. A retrospective study on the age of recovery of all childhood-onset Leber hereditary optic neuropathy patients reported in the literature suggested that this process was probably related with pubertal changes.
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Affiliation(s)
- Sonia Emperador
- Departamento de Bioquímica, Biología Molecular y Celular, Universidad de Zaragoza, Zaragoza, Spain.,Instituto de Investigación Sanitaria de Aragón (IIS Aragón), Zaragoza, Spain.,Centro de Investigaciones Biomédicas En Red de Enfermedades Raras (CIBERER), Barcelona, Spain
| | - Mariona Vidal
- Servicio de Oftalmología Pediátrica, Hospital Sant Joan de Déu, Barcelona, Spain
| | - Carmen Hernández-Ainsa
- Departamento de Bioquímica, Biología Molecular y Celular, Universidad de Zaragoza, Zaragoza, Spain.,Instituto de Investigación Sanitaria de Aragón (IIS Aragón), Zaragoza, Spain
| | - Cristina Ruiz-Ruiz
- Departamento de Bioquímica, Biología Molecular y Celular, Universidad de Zaragoza, Zaragoza, Spain
| | - Daniel Woods
- Departamento de Bioquímica, Biología Molecular y Celular, Universidad de Zaragoza, Zaragoza, Spain
| | - Ana Morales-Becerra
- Servicio de Oftalmología Pediátrica, Hospital Sant Joan de Déu, Barcelona, Spain
| | - Jorge Arruga
- Servicio de Oftalmología, Hospital Universitario de Bellvitge, L'Hospitalet de Llobregat, Barcelona, Spain
| | - Rafael Artuch
- Centro de Investigaciones Biomédicas En Red de Enfermedades Raras (CIBERER), Barcelona, Spain.,Servicio de Bioquímica, Hospital Institut de Recerca Sant Joan de Déu, Barcelona, Spain
| | - Ester López-Gallardo
- Departamento de Bioquímica, Biología Molecular y Celular, Universidad de Zaragoza, Zaragoza, Spain.,Instituto de Investigación Sanitaria de Aragón (IIS Aragón), Zaragoza, Spain.,Centro de Investigaciones Biomédicas En Red de Enfermedades Raras (CIBERER), Barcelona, Spain
| | - M Pilar Bayona-Bafaluy
- Departamento de Bioquímica, Biología Molecular y Celular, Universidad de Zaragoza, Zaragoza, Spain.,Instituto de Investigación Sanitaria de Aragón (IIS Aragón), Zaragoza, Spain
| | - Julio Montoya
- Departamento de Bioquímica, Biología Molecular y Celular, Universidad de Zaragoza, Zaragoza, Spain.,Instituto de Investigación Sanitaria de Aragón (IIS Aragón), Zaragoza, Spain.,Centro de Investigaciones Biomédicas En Red de Enfermedades Raras (CIBERER), Barcelona, Spain
| | - Eduardo Ruiz-Pesini
- Departamento de Bioquímica, Biología Molecular y Celular, Universidad de Zaragoza, Zaragoza, Spain.,Instituto de Investigación Sanitaria de Aragón (IIS Aragón), Zaragoza, Spain.,Centro de Investigaciones Biomédicas En Red de Enfermedades Raras (CIBERER), Barcelona, Spain.,Fundación ARAID, Zaragoza, Spain
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Leber's Hereditary Optic Neuropathy-Gene Therapy: From Benchtop to Bedside. J Ophthalmol 2010; 2011:179412. [PMID: 21253496 PMCID: PMC3021870 DOI: 10.1155/2011/179412] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2010] [Revised: 10/07/2010] [Accepted: 11/12/2010] [Indexed: 02/06/2023] Open
Abstract
Leber's hereditary optic neuropathy (LHON) is a maternally transmitted disorder caused by point mutations in mitochondrial DNA (mtDNA). Most cases are due to mutations in genes encoding subunits of the NADH-ubiquinone oxidoreductase that is Complex I of the electron transport chain (ETC). These mutations are located at nucleotide positions 3460, 11778, or 14484 in the mitochondrial genome. The disease is characterized by apoplectic, bilateral, and severe visual loss. While the mutated mtDNA impairs generation of ATP by all mitochondria, there is only a selective loss of retinal ganglion cells and degeneration of optic nerve axons. Thus, blindness is typically permanent. Half of the men and 10% of females who harbor the pathogenic mtDNA mutation actually develop the phenotype. This incomplete penetrance and gender bias is not fully understood. Additional mitochondrial and/or nuclear genetic factors may modulate the phenotypic expression of LHON. In a population-based study, the mtDNA background of haplogroup J was associated with an inverse relationship of low-ATP generation and increased production of reactive oxygen species (ROS). Effective therapy for LHON has been elusive. In this paper, we describe the findings of pertinent published studies and discuss the controversies of potential strategies to ameliorate the disease.
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Jarrett SG, Lewin AS, Boulton ME. The importance of mitochondria in age-related and inherited eye disorders. Ophthalmic Res 2010; 44:179-90. [PMID: 20829642 PMCID: PMC2952187 DOI: 10.1159/000316480] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Mitochondria are critical for ocular function as they represent the major source of a cell's supply of energy and play an important role in cell differentiation and survival. Mitochondrial dysfunction can occur as a result of inherited mitochondrial mutations (e.g. Leber's hereditary optic neuropathy and chronic progressive external ophthalmoplegia) or stochastic oxidative damage which leads to cumulative mitochondrial damage and is an important factor in age-related disorders (e.g. age-related macular degeneration, cataract and diabetic retinopathy). Mitochondrial DNA (mtDNA) instability is an important factor in mitochondrial impairment culminating in age-related changes and pathology, and in all regions of the eye mtDNA damage is increased as a consequence of aging and age-related disease. It is now apparent that the mitochondrial genome is a weak link in the defenses of ocular cells since it is susceptible to oxidative damage and it lacks some of the systems that protect the nuclear genome, such as nucleotide excision repair. Accumulation of mitochondrial mutations leads to cellular dysfunction and increased susceptibility to adverse events which contribute to the pathogenesis of numerous sporadic and chronic disorders in the eye.
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Affiliation(s)
- Stuart G. Jarrett
- Department of Molecular and Biomedical Pharmacology, College of Medicine, University of Kentucky, Lexington, Ky., USA
| | - Alfred S. Lewin
- Department of Molecular Genetics, University of Florida, Gainesville, Fla., USA
| | - Michael E. Boulton
- Department of Anatomy and Cell Biology, College of Medicine, University of Florida, Gainesville, Fla., USA
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Late-onset Leber hereditary optic neuropathy mimicking Susac’s syndrome. J Neurol 2010; 257:1999-2003. [DOI: 10.1007/s00415-010-5649-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2010] [Revised: 06/22/2010] [Accepted: 06/28/2010] [Indexed: 10/19/2022]
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Puomila A, Hämäläinen P, Kivioja S, Savontaus ML, Koivumäki S, Huoponen K, Nikoskelainen E. Epidemiology and penetrance of Leber hereditary optic neuropathy in Finland. Eur J Hum Genet 2007; 15:1079-89. [PMID: 17406640 DOI: 10.1038/sj.ejhg.5201828] [Citation(s) in RCA: 135] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
We have performed an entire-population-based survey of the epidemiology and penetrance of Leber hereditary optic neuropathy (LHON) in Finland - a country that is among the best-studied genetic isolates in the world. During our long-term clinical follow-up period since 1970, we have so far identified 36 LHON families in Finland, comprised of almost 1000 family members. Counting the unaffected family members has been possible thanks to accessible genealogical records, and this has improved the accuracy of our penetrance figures by minimizing the sample bias. Our results, although confirming some well-known features of LHON, indicate that the overall penetrance of LHON is lower than previously estimated, and that affected females have a higher incidence of affected offspring compared to the unaffected females. The prevalence of LHON in Finland is 1:50 000, and one in 9000 Finns is a carrier of one of the three LHON primary mutations.
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Affiliation(s)
- Anu Puomila
- Department of Medical Genetics, University of Turku, Turku, Finland.
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Korpelainen H. The evolutionary processes of mitochondrial and chloroplast genomes differ from those of nuclear genomes. Naturwissenschaften 2004; 91:505-18. [PMID: 15452701 DOI: 10.1007/s00114-004-0571-3] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
This paper first introduces our present knowledge of the origin of mitochondria and chloroplasts, and the organization and inheritance patterns of their genomes, and then carries on to review the evolutionary processes influencing mitochondrial and chloroplast genomes. The differences in evolutionary phenomena between the nuclear and cytoplasmic genomes are highlighted. It is emphasized that varying inheritance patterns and copy numbers among different types of genomes, and the potential advantage achieved through the transfer of many cytoplasmic genes to the nucleus, have important implications for the evolution of nuclear, mitochondrial and chloroplast genomes. Cytoplasmic genes transferred to the nucleus have joined the more strictly controlled genetic system of the nuclear genome, including also sexual recombination, while genes retained within the cytoplasmic organelles can be involved in selection and drift processes both within and among individuals. Within-individual processes can be either intra- or intercellular. In the case of heteroplasmy, which is attributed to mutations or biparental inheritance, within-individual selection on cytoplasmic DNA may provide a mechanism by which the organism can adapt rapidly. The inheritance of cytoplasmic genomes is not universally maternal. The presence of a range of inheritance patterns indicates that different strategies have been adopted by different organisms. On the other hand, the variability occasionally observed in the inheritance mechanisms of cytoplasmic genomes reduces heritability and increases environmental components in phenotypic features and, consequently, decreases the potential for adaptive evolution.
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Affiliation(s)
- Helena Korpelainen
- Department of Applied Biology, University of Helsinki, PO Box 27, 00014, Helsinki, Finland.
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Urata M, Wada Y, Kim SH, Chumpia W, Kayamori Y, Hamasaki N, Kang D. High-sensitivity detection of the A3243G mutation of mitochondrial DNA by a combination of allele-specific PCR and peptide nucleic acid-directed PCR clamping. Clin Chem 2004; 50:2045-51. [PMID: 15364886 DOI: 10.1373/clinchem.2004.033761] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND The A3243G mutation of mitochondrial DNA (mtDNA) is involved in many common diseases, including diabetes mellitus and mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS). For detection of this mutation, allele-specific PCR is highly sensitive but requires strict control of PCR conditions; it thus is not adequate for a routine clinical test. We aimed to develop a routinely available PCR method for quantitative detection of low-level heteroplasmy of the A3243G mutation. METHODS Quantitative allele-specific PCR for the A3243G mutation was performed in the presence of peptide nucleic acid (PNA), in which PNA is complementary to the wild-type mtDNA, with one primer having a 3' end matched to nucleotide position 3243 of the mutant. RESULTS With our method, amplification of wild-type mtDNA was suppressed 7000-fold compared with amplification of the mutant mtDNA under a broad range of conditions: DNA, 5-100 ng; annealing temperature, 61-66 degrees C; and PNA, 1.5-3.5 micromol/L. Hence, 0.1% heteroplasmy of the A3243G mutation can be reliably quantified by this method. Blood samples form 40 healthy volunteers showed <0.06% heteroplasmy, suggesting that 0.1% is diagnostically significant. CONCLUSIONS PNA maintains the specificity of allele-specific PCR over a wide range of conditions, which is important for routine clinical testing.
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Affiliation(s)
- Michiyo Urata
- Department of Clinical Chemistry and Laboratory Medicine, Kyushu University, Graduate School of Medical Sciences, Fukuoka, Japan
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