Topic
Nuclear DNA
About: Nuclear DNA is a research topic. Over the lifetime, 3933 publications have been published within this topic receiving 185830 citations.
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TL;DR: Within a species-rich limestone grassland community in Northern England a correlation has been established between nuclear DNA content and the timing and rate of leaf extension in the spring, supporting the hypothesis that natural selection has operated upon nuclearDNA content through the differential sensitivity of cell division and cell expansion to low temperature.
Abstract: Summary
Within a species-rich limestone grassland community in Northern England a correlation has been established between nuclear DNA content and the timing and rate of leaf extension in the spring. The data support the hypothesis that natural selection has operated upon nuclear DNA content through the differential sensitivity of cell division and cell expansion to low temperature. It is suggested that measurements of nuclear DNA content may provide an index of temporal niche differentiation in plant communities.
146 citations
TL;DR: The DNA-intercalating dyes ethidium bromide and acriflavin strongly inhibit the enzymatic synthesis of DNA catalyzed by rat liver mitochondrial DNA polymerase, and the mitochondrial enzyme is much more sensitive to these dyes.
146 citations
TL;DR: The results illustrate the potential for introgressive hybridization to produce substantial mito‐nuclear discordance and demonstrate that an individual's mitochondrial and nuclear genome may have strikingly different evolutionary histories resulting from non‐neutral processes and intrinsic differences in the inheritance and biology of these genomes.
Abstract: We investigated the extent and potential cause(s) of mitochondrial introgression within the polytypic North American Lycaeides species complex (Lepidoptera). By comparing population genetic structure based on mitochondrial DNA (COI and COII) and nuclear DNA (251 polymorphic amplified fragment length polymorphism markers), we detected substantial mito-nuclear discordance, primarily involving a single mitochondrial haplotype (h01), which is likely due to mitochondrial introgression between differentiated Lycaeides populations and/or species. We detected reduced mitochondrial genetic diversity relative to nuclear genetic diversity in populations where mitochondrial haplotype h01 occurs, suggesting that the spread of this haplotype was facilitated by selection. We found no evidence that haplotype h01 is associated with increased fitness (in terms of survival to eclosion, fresh adult weight, and adult longevity) in a polymorphic Lycaeides melissa population. However, we did find a positive association between mitochondrial haplotype h01 and infection by the endoparasitic bacterium Wolbachia in one out of three lineages tested. Linkage disequilibrium between mitochondrial haplotype h01 and Wolbachia infection status may have resulted in indirect selection favouring the spread of haplotype h01 in at least one lineage of North American Lycaeides. These results illustrate the potential for introgressive hybridization to produce substantial mito-nuclear discordance and demonstrate that an individual's mitochondrial and nuclear genome may have strikingly different evolutionary histories resulting from non-neutral processes and intrinsic differences in the inheritance and biology of these genomes.
145 citations
TL;DR: Analysis of 20 randomly selected DNA clones suggests that there are more than 5000 such rearrangement sites in the genome, and specific breakage and rejoining of DNA occurs extensively during development, and might play an essential role in nuclear differentiation.
145 citations
TL;DR: De novo thymidylate synthesis in mitochondria prevents uracil accumulation in mitochondrial DNA (mtDNA) and is essential for mtDNA integrity.
Abstract: The de novo and salvage dTTP pathways are essential for maintaining cellular dTTP pools to ensure the faithful replication of both mitochondrial and nuclear DNA. Disregulation of dTTP pools results in mitochondrial dysfunction and nuclear genome instability due to an increase in uracil misincorporation. In this study, we identified a de novo dTMP synthesis pathway in mammalian mitochondria. Mitochondria purified from wild-type Chinese hamster ovary (CHO) cells and HepG2 cells converted dUMP to dTMP in the presence of NADPH and serine, through the activities of mitochondrial serine hydroxymethyltransferase (SHMT2), thymidylate synthase (TYMS), and a novel human mitochondrial dihydrofolate reductase (DHFR) previously thought to be a pseudogene known as dihydrofolate reductase-like protein 1 (DHFRL1). Human DHFRL1, SHMT2, and TYMS were localized to mitochondrial matrix and inner membrane, confirming the presence of this pathway in mitochondria. Knockdown of DHFRL1 using siRNA eliminated DHFR activity in mitochondria. DHFRL1 expression in CHO glyC, a previously uncharacterized mutant glycine auxotrophic cell line, rescued the glycine auxotrophy. De novo thymidylate synthesis activity was diminished in mitochondria isolated from glyA CHO cells that lack SHMT2 activity, as well as mitochondria isolated from wild-type CHO cells treated with methotrexate, a DHFR inhibitor. De novo thymidylate synthesis in mitochondria prevents uracil accumulation in mitochondrial DNA (mtDNA), as uracil levels in mtDNA isolated from glyA CHO cells was 40% higher than observed in mtDNA isolated from wild-type CHO cells. These data indicate that unlike other nucleotides, de novo dTMP synthesis occurs within mitochondria and is essential for mtDNA integrity.
145 citations