![]() Each daughter cell is a clone of the parent cell. ![]() The bacterial cell then elongates and splits into two daughter cells each with identical DNA to the parent cell. Based on our findings we established a model describing the ultrastructure of plant centromeres and discuss it in comparison to previous models proposed for animals and plants. Binary fission begins when the DNA of the bacterium divides into two (replicates). Thus, we conclude that the formation of chromatin rings may appear in different plant species and tissues, but that it is not specific for centromere function. In addition, we found that a chromatin ring formation may also be caused by subtelomeric repeats in barley. However, varying centromere structures, as ring formations or globular organized chromatin fibers, were identified in different tissues of one and the same species. Binary fission begins with DNA replication. It became obvious, that a ring formation at centromeres may appear during mitosis, meiosis and in interphase nuclei in all species analyzed. (super-resolution) was applied to investigate the ultrastructure of centromere chromatin beyond the classical refraction limit of light. Furthermore, structured illumination microscopy. To test whether this behavior is present also in other plant species and tissues we analyzed Arabidopsis, rye, wheat, Aegilops and barley centromeres during cell divisions and in interphase nuclei by immunostaining and FISH. We observed the formation of chromatin ring structures at centromeres of somatic rye and Arabidopsis chromosomes. Key words: Cytogenetic effect, fragment chromosome, telophage bridge, acentric chromosome, View full-text In our opinion, the high micronuclei frequency observed in experimental sample was induced either by the lagging of whole chromosomes or the immobility of large acentric fragments. Fragment chromosomes with frequencies of 0.024% in the anaphase and 0.04% in the telophase were also observed. This kind of reproduction is seen in Amoeba and other organisms. In this process, the body first duplicates its genetic materials and then the body divides into two bodies by the process of cytokinesis. Using anaphase analysis, we established anaphase and telophase bridges, as well as chromosome fragments with frequencies of 0.11 % and 0.097%, respectively. Binary fission is a kind of asexual reproduction where a body separates into two new bodies with each body with its own copy of DNA. The highest frequency (1.79%) was shown by micronuclei. The cytogenetic analysis showed the absence of any mutations in the control and the presence of 2.231% in the test sample No 2. ![]() 2040 cells for the control No cells for the test sample No2. To compare cell division rate in determining the mitotic index, we examined a total of. A decreased cell division rate was established and deviations from the normal mitosis in the result of chromosome mutations were registered. These microbes reproduce rapidly at an exponential rate under favorable conditions. A study was made on the cytogenetic effects of chromium metal on meristematic cells of root tips in Allium cepa L, Here plant test-system Allium cepa was used in vivo. Bacteria are prokaryotic organisms that most commonly replicate by the asexual process of binary fission. ![]()
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