Vincristine is an alkaloid widely used as an antineoplastic agent. In eukaryotic cells the drug causes blockage in the G2 phase of the cell cycle and an increase in the frequency of sister chromatid exchanges. Due to the fact that germinating Aspergillus nidulans cells spend most of their cycle in G2 phase, they provide an excellent system for the study of mitotic crossing-over. Taking into account that mitotic crossing-over occurs during G2 period, the evaluation of recombinagenic and aneugenic potential of vincristine is provided with regard to two diploid strains of A. nidulans: a wild strain (uvsH+//uvsH+) and a defective one in DNA repair (uvsH//uvsH). Drug toxicity and its effect on the asexual cycle of A. nidulans has been evaluated as well. Treatment of both strains with vincristine did not change colony growth in the culture, however cytological analyses showed aberrant conidiophores. Recombinagenic potential of vincristine was evaluated by induction of gene homozygosis originally present in heterozygosity diploid strains (Homozygotization Index). Results show that vincristine induces mitotic crossing-over and higher frequency of aneuploid mitotic segregants. The results also show the recombinagenic and aneuploidogenic potential of vincristine and suggest its participation in the induction of secondary malignancies.
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http://dx.doi.org/10.4067/s0716-97602002000100006 | DOI Listing |
Front Cell Dev Biol
September 2024
Department of Animal Sciences Purdue University West Lafayette, West Lafayette, IN, United States.
Embryo development is stimulated by calcium (Ca) signals that are generated in the egg cytoplasm by the fertilizing sperm. Eggs are formed via oogenesis. They go through a cell division known as meiosis, during which their diploid chromosome number is halved and new genetic combinations are created by crossing over.
View Article and Find Full Text PDFCan J Ophthalmol
December 2024
Discipline of Ophthalmology, Sydney Medical School, University of Sydney, Sydney, Australia; Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, BC.
Objective: To report corneal epithelial and corneal endothelial cell (CEC) changes following Descemet stripping only (DSO) with and without topical ripasudil using in vivo confocal microscopy (IVCM).
Methods: Prospective interventional case series of patients who underwent DSO for Fuchs endothelial dystrophy with or without postoperative topical ripasudil (4%, 6 times per day). Patients underwent IVCM (ConfoScan 3; NIDEK Technologies, Padova, Italy) at baseline, monthly until corneal clearance, and then every 6 months.
Toxicology
March 2024
Institute of Biodiversity and Ecosystem Research, Bulgarian Academy of Sciences, 2 Gagarin str., Sofia 1113, Bulgaria.
The present work aims to clarify the genotype differences of a model organism Saccharomyces cerevisiae in response to bee venom. The study evaluated various endpoints including cell survival, induction of physiologically active superoxide anions, mitotic gene conversion, mitotic crossing-over, reverse mutations, DNA double-strand breaks, and Ty1 retrotransposition. The role of the intact mitochondria and the YAP1 transcription factor was also evaluated.
View Article and Find Full Text PDFNucleic Acids Res
April 2024
Department of Life Sciences, Chung-Ang University, Seoul 06974, South Korea.
Annu Rev Genet
November 2023
Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts, USA; email:
The raison d'être of meiosis is shuffling of genetic information via Mendelian segregation and, within individual chromosomes, by DNA crossing-over. These outcomes are enabled by a complex cellular program in which interactions between homologous chromosomes play a central role. We first provide a background regarding the basic principles of this program.
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