Chromosome Pairing and Fertility in Polyploids
Christopher B. Gillies in Fertility and Chromosome Pairing: Recent Studies in Plants and Animals, 2020
Polyploidy is the presence in cells or tissues of an organism of three or more copies of the basic set of chromosomes (the haploid genome). Occasional polyploid cells occur in many types of tissues in both plants and animals. Many important crop plants are polyploid, and polyploidy has undoubtedly been important in the evolution of many plants and probably some animals. More than one third of angiosperms are polyploid1 and 70 to 80% may have polyploidy in their ancestry. In contrast, polyploidy in sexually reproducing animals is rare. The usual explanation advanced is that polyploidy would disturb the sex chromosome balance, leading to intersexes,2,3 but this is not always the case. Nevertheless, approximately 10% of human zygotes are polyploid, although most spontaneously abort and the rare liveborns do not survive long.4,5 Sexually reproducing polyploid species do occur naturally among the amphibia6,8 and fish,9,10 but polyploidy in animals is often associated with parthenogenic reproduction, e.g., amphibia, fish, reptiles,11 nematodes,12,13 earthworms,14 and insects.15
A Brief Survey of Early Indigenous Knowledge Which Influenced Modern Agronomic Practices
David R. Katerere, Wendy Applequist, Oluwaseyi M. Aboyade, Chamunorwa Togo in Traditional and Indigenous Knowledge for the Modern Era, 2019
The indigenous farmers from the region were able to use their knowledge to correctly distinguish tetraploid (Solanum tuberosum ssp. andigena) and diploid (S. goniocalyx, S. phureja, and S. stenotomum) species without any modern methods such as chromosome counting or isozymes (Quiros et al. 1990). This indicated, at least in part, that folkloric methods of selection for this crop were effective. At present, distinguishing between diploid, triploid, and tetraploid forms of the potato is achievable through the use of a range of sophisticated approaches, including electrophoretic (Bauw et al. 2006), flow cytometric (Uijtewaal 1987), and cytogenetic (Dong et al. 2000) methods. DNA marker technologies (Bryan et al. 1999, Nakagawa and Hosaka 2002, Hardigan et al. 2017) are now used for rapid and accurate selections of distinct forms of the potato in genetic improvement programs.
General Radiation Cytopathology
George W. Casarett in Radiation Histopathology, 2019
Certain of the gross structural aberrations or rearrangements of chromosomes are known to impair cell survival. As the centromeres are responsible for separation of chromatid strands, acentric fragments may become incorporated into daughter cells as micronuclei, but their distribution in suceeding generations will be haphazard, and cell death resulting from genie imbalance may occur. Any dicentric chromatids undergo a similar hazard, as in 50% of cases, at anaphase the two centromeres will pass to opposite poles and an anaphase bridge will be formed. Such a bridge may break, allowing the cell to complete division, but genic imbalance of the daughter cells will probably result. Alternatively the cell may divide abnormally, or not divide and a tetraploid may be formed. The cell which survives the first generation will be subjected to similar stresses at succeeding generations. Duplications or deficiencies can occur from intrachromosomal chromatid exchanges and impair survival.
Reproductive outcomes in couples with sporadic miscarriage after embryonic chromosomal microarray analysis
Published in Annals of Medicine, 2023
Zhengyi Xia, Ran Zhou, Yiming Li, Lulu Meng, Mingtao Huang, Jianxin Tan, Fengchang Qiao, Hui Zhu, Ping Hu, Qiaoying Zhu, Zhengfeng Xu, Yan Wang
Numerical chromosomal abnormalities were the most frequent abnormal finding, including 542 (48.0%) with aneuploidies and 87 (7.7%) with polyploidies. Among the cases with aneuploidies, 95.4% (517/542) of these cases were identified as single aneuploidies, and multiple aneuploidies composed the remaining 4.6% (25/542). With the exception of chromosomes 1 and 19, single aneuploidies were detected in all chromosomes. Trisomies represented the majority among the cases with single aneuploidies (420/517, 81.2%), and others were monosomies (97/517, 18.8%). With respect to trisomies, trisomy 16 was the most common (142/420, 33.8%), followed by trisomy 22 (64/420, 15.2%) and trisomy 21 (28/420, 6.7%). Monosomies were observed in chromosomes X (95/97, 97.9%), 8 (1/97, 1.0%) and 21 (1/97, 1.0%). Among the cases with polyploidies, 85 (97.7%) were triploidy and two (2.3%) were tetraploidy. In addition, four cases (0.4%) with whole-genome UPD were identified in our cohort.
Investigation of apoptotic and antiproliferative effects of Turkish natural tetraploids Trifolium pratense L. extract on C6 glioblastoma cells via light and electron microscopy
Published in Ultrastructural Pathology, 2023
Gamze Tanrıverdi, Aynur Abdulova, Hatice Çölgeçen, Havva Atar, Belisa Kaleci, Tuğba Ekiz-Yılmaz
Therefore, the aim of this study was to reveal the efficacy and the possible antitumoral effects of Turkish natural tetraploid Trifolium pratense L. extract on C6 Glioblastoma cells. For this purpose, five different concentrations of this extract were applied to C6 cells for promoting cell death and were tested in an in vitro model. At the end of 24 h and 48 hours incubation time, the plant extract reduced the CCK-8 index in all the different dose groups compared to the control group. IC50 values of the experimental doses were as followed: 12.5 µg/mL in 24 h, 12.5 µg/mL and 25 µg/mL in the 48 h, in the experimental groups, respectively. Apoptotic markers had highest levels on the same doses. These results showed that the Turkish natural tetraploid Trifolium pratense L. extract decreased cell proliferation and induced apoptosis in a time and dose-dependent manner. In a similar study, Khazaei M et al., applied Trifolium pratense L. hydroalcoholic extract together with TMZ and reported that there had been a significant synergy between these two agents and they had decreased cell proliferation and induced apoptosis.33 Sehm et al. also studied the biochanin A and genistein isoflavones, provided from Trifolium pratense L. and found out about their inhibitory effects on U251 glioma cells proliferation and the enhancing apoptotic effects on the same cells.34 In addition, Li Y et al. reported that biochanin A has been effective on lung cancer cells via cell cycle arrest and increasing apoptotic markers like caspase-3, p21, and bcl-2.35
Lung damage by thoron progenies versus possible damage redemption by lung stem cells: a perspective
Published in International Journal of Radiation Biology, 2020
Debajit Chaudhury, Utsav Sen, Nagesh N. Bhat, Bijay Kumar Sahoo, Sudheer Shenoy P, Bipasha Bose
Ionizing radiations are responsible for the mitotic catastrophe that causes hyper-amplification and over duplication of chromosomes, resulting in micronuclei formation (Seideman et al. 2011). In the lung somatic and stem cells following thoron inhalation, the status of the cell cycle checkpoint proteins, DNA strand breaks, concerning thoron dosages will comprise an important aspect of the mechanistic studies. Cells that escape mitotic arrest often fail cytokinesis, resulting in tetraploid DNA content and abnormal nuclei forming giant cells thereby leading to cancer initiation (Vogel et al. 2007). Recent studies have also suggested the ionizing radiation-induced necroptosis (programmed necrosis) through the engagement of ligand-DR (Death receptor) under the conditions where the apoptotic pathway is either blocked or deficient (Degterev and Yuan 2008). Here, in context with thoron inhalation, the decay of thoron progenies leads to the emission of radiation that might be involved in necroptosis and is worth investigating.
Related Knowledge Centers
- Eukaryote
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