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タグ「Mitochondrial DNA」

Historical mutation rates predict susceptibility to radiation in Chernobyl birds

ecology・environment

Title: Historical mutation rates predict susceptibility to radiation in Chernobyl birds

Author: MØLLER, A. P. / ERRITZøE, J. / KARADAS, F. / MOUSSEAU, T. A.

Reference: Journal of Evolutionary Biology, 23 (10), p.2132-2142, Aug 2010

doi:　 10.1111/j.1420-9101.2010.02074.x

Keywords: antioxidants; birds; extreme environmental perturbation; mitochondrial DNA; substitution rates

Abstract: Extreme environmental perturbations are rare, but may have important evolutionary consequences. Responses to current perturbations may provide important information about the ability of living organisms to cope with similar conditions in the evolutionary past. Radioactive contamination from Chernobyl constitutes one such extreme perturbation, with significant but highly variable impact on local population density and mutation rates of different species of animals and plants. We explicitly tested the hypothesis that species with strong impacts of radiation on abundance were those with high rates of historical mutation accumulation as reflected by cytochrome b mitochondrial DNA base-pair substitution rates during past environmental perturbations. Using a dataset of 32 species of birds, we show higher historical mitochondrial substitution rates in species with the strongest negative impact of local levels of radiation on local population density. These effects were robust to different estimates of impact of radiation on abundance, weighting of estimates of abundance by sample size, statistical control for similarity in the response among species because of common phylogenetic descent, and effects of population size and longevity. Therefore, species that respond strongly to the impact of radiation from Chernobyl are also the species that in the past have been most susceptible to factors that have caused high substitution rates in mitochondrial DNA.

URL:http://onlinelibrary.wiley.com/doi/10.1111/j.1420-9101.2010.02074.x/abstract

 

Molecular features of mitochondrial DNA in radiation-associated thyroid tumors

thyroid cancer

 

Title: Molecular features of mitochondrial DNA in radiation-associated thyroid tumors

Author: Rogounovitch, Tatiana I. / Saenko, Vladimir A. / Shimizu-Yoshida, Yuki / Abrosimov, Aleksandr Yu. / Lushnikov, Eugeny F. / Roumiantsev, Pavel O. / Ohtsuru, Akira / (…) / Yamashita, Shunichi

Reference: International Congress Series, 1258, p.163-168, Nov 2003

doi: 10.1016/S0531-5131(03)01151-8

Keywords: Mitochondrial DNA; Large-scale deletions; Common deletion;         Radiation-associated thyroid tumors

Abstract: DNA samples from tumor and normal thyroid tissues of adult patients with papillary thyroid carcinoma (PTC) and follicular adenoma (FA), who lived in the Chernobyl radioactive zones of Russia and control groups of Japanese patients with PTC, were quantitatively analyzed for the mitochondrial DNA (mtDNA) content and prevalence of the common deletion (CD) and large-scale deletions (LSD). In most tumor tissues, level of mtDNA was elevated. CD and LSD were detected in every sample examined. The quantity of LSD in mtDNA was elevated in most tumor tissues, especially in the radiation-associated group of samples. Also in this group, in the tumor tissue of both PTC and FA, there was a highly significant positive correlation between the number of LSD and the level of relative mtDNA content. In contrast, in sporadic PTCs, this correlation did not occur. Normal tissue samples displayed a statistically insignificant tendency to negative association with relative mtDNA content. Thus, determination of the LSD levels and mtDNA content may be useful for the molecular distinction of radiation-associated and spontaneous thyroid tumors.

URL: http://www.sciencedirect.com/science/article/pii/S0531513103011518

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