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Full-Text Articles in Life Sciences
Genomic Instability At A Polypurine/Polypyrimidine Repeat Sequence, Nathen S. Zavada
Genomic Instability At A Polypurine/Polypyrimidine Repeat Sequence, Nathen S. Zavada
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Microsatellite repeat sequences have been shown to induce replication stalling, fork collapse, double-strand breaks (DSBs), and possibly stimulate break-induced replication. In this study we use a dual-fluorescent HeLa model that is designed to monitor recombination at an ectopic site through use of flow cytometry and inverse PCR with a microsatellite in the lagging strand for DNA synthesis. To test the stability of the 78 bp polypurine/pyrimidine repeat from the PDK1 locus, we subjected cells to replication stress drugs designed to induce DSBs and measure break-induced replication (BIR). The study revealed that polypurine repeat cells undergo endogenous stress contributing to instability …
Identification Of New Metabolic Mutations In The Fission Yeast Schizosaccharomyces Pombe That Sensitize The Cell To Hydroxyurea, Alaa Mahdi
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Cancer is a life-threatening illness and innovative research is therefore required to fuel the development of new anti-cancer therapies. As an anti-proliferative drug, hydroxyurea (HU) has been used in the treatment of various neoplastic and non-neoplastic diseases such as sickle cell anemia, psoriasis, and viral infections. HU is a well-known inhibitor of ribonucleotide reductase (RNR), an enzyme that generates dNTPs for DNA replication and repair. In our genetic screen in fission yeast looking for mutants with defects in checkpoint response, we also found a set of mutants that are highly sensitive to HU but with a functional checkpoint response. It …
Genetic Study Of Checkpoint Defects Of The Mus81-1 Mutant In The Fission Yeast Schizosaccharomyces Pombe, Darlington Osei Abrefa
Genetic Study Of Checkpoint Defects Of The Mus81-1 Mutant In The Fission Yeast Schizosaccharomyces Pombe, Darlington Osei Abrefa
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In response to various perturbations of DNA replication, the DNA replication checkpoint is activated in eukaryotes to stimulate a cascade of cellular responses that are crucial for maintaining genome stability and cell survival. Defects in the checkpoint pathway result in mutations and genome instability, which is a hallmark for cancers. This study used a genetic approach to identify a mutation in the MMS (methyl methanesulfonate) and UV-sensitive protein Mus81, a DNA repair enzyme that resolves aberrant DNA structures through the homologous recombination pathway. We show that a single missense mutation, identified in fission yeast mus81-1, causes moderate reduction in the …
Identification Of A Hybrid Lethal Gene On The X Chromosome Of Caenorhabditis Briggsae, John Kelly Dougherty
Identification Of A Hybrid Lethal Gene On The X Chromosome Of Caenorhabditis Briggsae, John Kelly Dougherty
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Two closely related Caenorhabditis species, C. briggsae and C. nigoni are cross fertile and produce viable adult progeny. From C. nigoni mothers, F1 adult females are viable and fertile, F1 males are viable but sterile. In crosses that utilize C. nigoni males and C. briggsae hermaphrodites produce viable adult F1 females but F1 males arrest during embryogenesis. A mutation in the Cbr-him-8 gene is a recessive maternal-effect suppressor of male-specific lethality. Hybrid crosses with cbr-him-8 mutant mothers produce viable adult male progeny. The HIM-8 protein in C. elegans is required for the pairing of X-chromosomes during meiosis. This function is …
Genotyping For Response To Physical Training, Stacy Simmons
Genotyping For Response To Physical Training, Stacy Simmons
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Understanding the inter-individual variability in physical fitness performance has been the focus of scientific research for decades especially in the United States military. Injury and physical inadequacy cost the U.S military millions of dollars every year. The project PHITE (Precision High Intensity Training through Epigenetics) was funded to investigate this personal complex trait by combing the genetic and epigenetic (non-shared environmental factors) contributions into a single model for physical training response. This project is set up as having 150 male and female recruits between the ages of 18-27 years old. Each participant is randomly put blind into either a high …
Multi-Locus Evidence Of A Late Pleistocene Divergence And Sex-Biased Dispersal In The North American Wood Duck (Aix Sponsa), Christopher T. Bigley
Multi-Locus Evidence Of A Late Pleistocene Divergence And Sex-Biased Dispersal In The North American Wood Duck (Aix Sponsa), Christopher T. Bigley
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The Pleistocene was characterized by fluctuations in climate causing repeated advances and retreats of glacial ice. The advancing ice sheets caused habitat fragmentation which initiated population divergence and speciation events between eastern and western avian populations within northern temperate forests. Based on mitochondrial DNA (mtDNA) control region sequences, North American Wood Duck (Aix sponsa) populations fit this model of divergence. However, mtDNA is maternally inherited, and thus may not reflect the genomic history of this species, because of male biased-dispersal, selection, or stochastic lineage sorting. To test the "Late Pleistocene divergence" hypothesis, I sequenced 11 independent nuclear introns (nuDNA) for …