Abstract Objective We identify ionizing radiation-induced mitochondrial DNA （mtDNA） deletions in human lymphocytes and their distribution in normal populations. Methods Long-range polymerase chain reactions （PCR） ...Abstract Objective We identify ionizing radiation-induced mitochondrial DNA （mtDNA） deletions in human lymphocytes and their distribution in normal populations. Methods Long-range polymerase chain reactions （PCR） using two pairs of primers specific for the human mitochondrial genome were used to analyze the lymphoblastoid cell line following exposure to 10 Gy 6~Co y-rays. Limited-condition PCR, cloning and sequencing techniques were applied to verify the mtDNA deletions detected with long-range PCR. Human peripheral blood samples were irradiated with 0, 2 and 6 Gy ^60Co y-rays, and real-time PCR analysis was performed to validate the mtDNA deletions. In order to know the distribution of mtDNA deletions in normal population, 222 healthy Chinese adults were also investigated. Results Two mtDNA deletions, a 7455-bp deletion （nt475-nt7929 in heavy strand） and a 9225-bp deletion （nt7714 -nt369 in heavy strand）, occurring between two 8-bp direct repeats, were identified in lymphoblastoid cells using long-range PCR, limited-condition PCR and sequencing. These results were also observed for ^60Co y-rays irradiated human peripheral blood cells. Conclusion Two novel mtDNA deletions, a 7455-bp deletion and a 9225-bp deletion, were induced by ionizing radiation. The rate of the mtDNA deletions within a normal population was related to the donors＇ age, but was independent of gender.展开更多
To investigate the distribution of mitochondria ONA 4 977 bp deletion, a common deletion （CD）, in normal populations of Chinese, human peripheral blood samples from sixty healthy donors were collected, and levels of...To investigate the distribution of mitochondria ONA 4 977 bp deletion, a common deletion （CD）, in normal populations of Chinese, human peripheral blood samples from sixty healthy donors were collected, and levels of the CD in genomic DNA from the samples were detected using real-time PCR. The results showed that the CD was found in 27 health donors, with its positive rate being 45% （27/60）. The CD ratio was between 0 and 0.000308%, and not affected by age and gender in sixty healthy donors. Our studies indicate that the CD ratio is low, and do not show the age-dependent accumulation and any gender difference in peripheral whole blood from the normal Chinese population.展开更多
基金supported by the National Natural Science Foundation of China(No.30570551and No.30870749)the Beijing Natural Science Foundation(No.7053073)
文摘Abstract Objective We identify ionizing radiation-induced mitochondrial DNA （mtDNA） deletions in human lymphocytes and their distribution in normal populations. Methods Long-range polymerase chain reactions （PCR） using two pairs of primers specific for the human mitochondrial genome were used to analyze the lymphoblastoid cell line following exposure to 10 Gy 6~Co y-rays. Limited-condition PCR, cloning and sequencing techniques were applied to verify the mtDNA deletions detected with long-range PCR. Human peripheral blood samples were irradiated with 0, 2 and 6 Gy ^60Co y-rays, and real-time PCR analysis was performed to validate the mtDNA deletions. In order to know the distribution of mtDNA deletions in normal population, 222 healthy Chinese adults were also investigated. Results Two mtDNA deletions, a 7455-bp deletion （nt475-nt7929 in heavy strand） and a 9225-bp deletion （nt7714 -nt369 in heavy strand）, occurring between two 8-bp direct repeats, were identified in lymphoblastoid cells using long-range PCR, limited-condition PCR and sequencing. These results were also observed for ^60Co y-rays irradiated human peripheral blood cells. Conclusion Two novel mtDNA deletions, a 7455-bp deletion and a 9225-bp deletion, were induced by ionizing radiation. The rate of the mtDNA deletions within a normal population was related to the donors＇ age, but was independent of gender.
基金supported by grants from the building project for the National Key Clinical Special Department of China(No.2011-17)the Medical Science and Technology Foundation of Henan Province(No.201204123)the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘To investigate the distribution of mitochondria ONA 4 977 bp deletion, a common deletion （CD）, in normal populations of Chinese, human peripheral blood samples from sixty healthy donors were collected, and levels of the CD in genomic DNA from the samples were detected using real-time PCR. The results showed that the CD was found in 27 health donors, with its positive rate being 45% （27/60）. The CD ratio was between 0 and 0.000308%, and not affected by age and gender in sixty healthy donors. Our studies indicate that the CD ratio is low, and do not show the age-dependent accumulation and any gender difference in peripheral whole blood from the normal Chinese population.
