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991.
Yasuo Ina Masashi Mizokami Kenichi Ohba Takashi Gojobori 《Journal of molecular evolution》1994,38(1):50-56
Molecular evolutionary analyses were carried out to elucidate the phylogenetic relationships, the evolutionary rate, and the divergence times of hepatitis C viruses. Using the nucleotide sequences of the viruses isolated from various locations in the world, we constructed phylogenetic trees. The trees showed that strains isolated from a single location were not necessarily clustered as a group. This suggests that the viruses may be transferred with blood on a worldwide scale. We estimated the evolutionary rates at synonymous and nonsynonymous sites for all genes in the viral genome. We then found that the rate (1.35 × 10–3 per site per year) at synonymous sites for the C gene was much smaller than those for the other genes (e.g., 6.29 × 10–3 per site per year for the E gene). This indicates that a special type of functional constraint on synonymous substitutions may exist in the C gene. Because we found an open reading frame (ORF) with the C gene region, the possibility exists that synonymous substitutions for the C gene are constrained by the overlapping ORF whose reading frame is different from that of the C gene. Applying the evolutionary rates to the trees, we also suggest that major groups of hepatitis C viruses diverged from their common ancestor several hundred years ago.
Correspondence to: T. Gojobori 相似文献
992.
993.
Ronan Sulpice Agata Sienkiewicz-Porzucek Sonia Osorio Ina Krahnert Mark Stitt Alisdair R. Fernie Adriano Nunes-Nesi 《Amino acids》2010,39(4):1055-1066
Transgenic tomato (Solanum lycopersicum) plants were generated targeting the cytosolic NADP-dependent isocitrate dehydrogenase gene (SlICDH1) via the RNA interference approach. The resultant transformants displayed a relatively mild reduction in the expression
and activity of the target enzyme in the leaves. However, biochemical analyses revealed that the transgenic lines displayed
a considerable shift in metabolism, being characterized by decreases in the levels of the TCA cycle intermediates, total amino
acids, photosynthetic pigments, starch and NAD(P)H. The plants showed little change in photosynthesis with the exception of
a minor decrease in maximum photosynthetic efficiency (F
v/F
m), and a small decrease in growth compared to the wild type. These results reveal that even small changes in cytosolic NADP-dependent
isocitrate dehydrogenase activity lead to noticeable alterations in the activities of enzymes involved in primary nitrate
assimilation and in the synthesis of 2-oxoglutarate derived amino acids. These data are discussed within the context of current
models for the role of the various isoforms of isocitrate dehydrogenase within plant amino acid metabolism. 相似文献
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