The repair of gamma-ray induced DNA single and double-strand breaks was looked at in wild type and rad18-2 strains of the yeast Saccharomyces cerevisiae using sucrose gradient centrifugation. It was found that rad18-2 diploid cells could repair single and double-strand breaks induced by gamma-rays. It was also found that rad18-2 cells experienced a breakup of their DNA during post-irradiation incubation to a size smaller than seen in cells just receiving irradiation. This breakup of DNA in rad18-2 cells is not degradation due to cell death since wild type cells irradiated to similar low survival levels do not show this breakup of DNA with 8 h incubation. The breakup of DNA in rad18-2 cells is not due to replication gaps being formed by synthesis on a damaged template since treatment of rad18-2 a mating type cells with alpha factor, to prevent initiation of DNA synthesis, does not prevent breakup of the DNA.
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Elife
December 2024
Department of Biological Sciences, University of Memphis, Memphis, United States.
The rise of angiosperms to ecological dominance and the breakup of Gondwana during the Mesozoic marked major transitions in the evolutionary history of insect-plant interactions. To elucidate how contemporary trophic interactions were influenced by host plant shifts and palaeogeographical events, we integrated molecular data with information from the fossil record to construct a time tree for ancient phytophagous weevils of the beetle family Belidae. Our analyses indicate that crown-group Belidae originated approximately 138 Ma ago in Gondwana, associated with Pinopsida (conifer) host plants, with larvae likely developing in dead/decaying branches.
View Article and Find Full Text PDFEMBO J
September 2024
Vanderbilt University School of Medicine, Nashville, TN, USA.
Replication complexes, or replisomes, are removed from DNA upon completion of DNA synthesis, but the importance of replisome removal, as well as how cells might respond to defects in this process, has remained elusive. New work by Polo Rivera et al (2024) and Olson et al (2024) reveals that leftover replisomes are an obstacle to replication and provides a first glimpse into the biochemical mechanisms that solve this problem.
View Article and Find Full Text PDFCladistics
December 2024
Departament Biologia Evolutiva, Ecologia i Ciències Ambientals, Universitat de Barcelona, Av. Diagonal 645, E-08028, Barcelona, Spain.
Mol Phylogenet Evol
October 2024
Department of Ecosystems in the Barents Region, Norwegian Institute of Bioeconomy Research, Svanvik, Norway.
Phylogenomic approaches have recently helped elucidate various insect relationships, but large-scale comprehensive analyses on relationships within sawflies and woodwasps are still lacking. Here, we infer the relationships and long-term biogeographic history of these hymenopteran groups using a large dataset of 354 UCE loci collected from 385 species that represent all major lineages. Early Hymenoptera started diversifying during the Early Triassic ∼249 Ma and spread all over the ancient supercontinent Pangaea.
View Article and Find Full Text PDFBiophys J
April 2024
Competence Center Bioinformatics, Institute for Applied Computer Science, Hochschule Stralsund, Stralsund, Germany. Electronic address:
Recent research highlights the significance of the three-dimensional structure of chromatin in regulating various cellular processes, particularly transcription. This is achieved through dynamic chromatin structures that facilitate long-range contacts and control spatial accessibility. Chromatin consists of DNA and a variety of proteins, of which histones play an essential structural role by forming nucleosomes.
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