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Products of Conception
Published in Carlos Simón, Carmen Rubio, Handbook of Genetic Diagnostic Technologies in Reproductive Medicine, 2022
Nasser Al-Asmar, Marcia Riboldi
Our group has used NGS/aCGH with STR for aneuploidy detection to analyze more than 2,500 POC cases: 675 by aCGH and 1,875 by NGS. Average maternal age was 35.3 ± 4.9 years and the mean gestational age at which the spontaneous miscarriage occurred was 7.9 ± 2.8 weeks. After three dissections from different locations in the piece of fetal tissue, we reduced the non-informativity rate due to MCC to 12.8%. We were able to provide results (either normal or abnormal) in 86.2% of cases. Notably, three dissections were done per POC sample to establish a lower rate of MCC. We also performed an internal study, taking six or nine samples when the first three were found to be MCC. If the first three dissections proved to be MCC, a larger number of dissections did not change the results. Therefore, when the first three dissections result in MCC, we recommend that no further dissections be performed. We found chromosomal abnormalities in up to 53.5% of cases. As expected, trisomies were the most common abnormality (74.3%) and 7.6% of cases had multiple aneuploidies. Among trisomies, chromosomes 15, 16, and 22 were the most prevalent at 13.3%, 17.6%, and 16.6%, respectively. In addition to trisomies, del/dups were found in 2.3% of cases. Monosomy 45,X was found in more than 9% of cases. Interestingly, we identified monosomy for autosomes in 1.8% of cases. Polyploidy was found in 4.6% of cases. Table 29.2 shows the detailed results.
Chromosome Pairing and Fertility in Polyploids
Published in Christopher B. Gillies, 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
Repeated DNA Sequences and Polyploidy in Cereal Crops
Published in S. K. Dutta, DNA Systematics, 2019
During evolution and in the process of speciation, changes in the amount of DNA per cell may arise due to: Polyploidy, which involves duplication of the entire basic chromosome complement of the species or of hybrids between two species as in amphiploidy.Aneuploidy, i.e., addition or deletion of some chromosomes.Changes in the number of accessory or so-called B chromosomes.Gains or loss of DNA without any change in the number of chromosomes.72
Gamma irradiation to induce beneficial mutants in proso millet (Panicum miliaceum L.): an underutilized food crop
Published in International Journal of Radiation Biology, 2022
Neethu Francis, Ravikesavan Rajasekaran, Iyanar Krishnamoorthy, Raveendran Muthurajan, Chitdeshwari Thiyagarajan, Senthil Alagarswamy
Mutation breeding is a very promising approach in creating new variation and developing genetic resources for crop improvement in proso millet. Through the present study, the optimum dose range for mutation induction through gamma has been concluded as 400 Gy. Despite the polyploid nature of the crop, a wide spectrum and high frequency of beneficial mutants have been detected in M2 generation. Mutation has broadened the variability in the crop significantly both for qualitative and quantitative traits. Indirect selection for yield attributing traits like FL area, NP, NT, PL, etc. in early generations (M2 and M3) was rewarding. It resulted in isolation of eight high yielding mutants, i.e. ATL1 400-11-1-3, ATL1 400-51-1-1, ATL1 400-51-1-3, ATL1 500-4-1-1, ATL1 500-5-1-8, ATL1 500-14-13-7, ATL1 500-36-8-1 and ATL1 500-45-3-11 in M4 generation. Hence, mutation breeding through gamma irradiation can be confidently employed in future breeding attempts in proso.
Role of inflammation in the malignant transformation of pleural mesothelial cells induced by multi-walled carbon nanotubes
Published in Nanotoxicology, 2020
Xiaopei Huang, Yijun Tian, Wenjing Shi, Jikuai Chen, Lang Yan, Lijun Ren, Xiaofang Zhang, Jiangbo Zhu
The genotoxicity of MWCNTs on macrophages and Met 5A cells was detected using a chromosome aberration assay. The groups were as follows: positive control group cyclophosphamide + Met 5A) and negative control group (DMSO + Met 5A). The other groups were: macrophages + Met 5A; MWCNTs + Met 5A; MWCNTs + macrophages + Met 5A. The final concentration of MWCNTs was 0.1 µg/mL with an exposure time of three months. Results demonstrated that chromosomal aberrations in the negative control group, positive control group, macrophages + Met 5A group, MWCNTs + Met 5A group, and MWCNTs + macrophages + Met 5A group were 1.0, 14.6, 0.8, 2.8, and 5.0%, respectively. Compared to the negative control group, the chromosome aberration rate of the MWCNTs + macrophages + Met 5A group and the MWCNTs + Met 5A group increased significantly (p < 0.05). Similarly, compared to the MWCNTs + Met 5A group, the chromosome aberration rate of the MWCNTs + macrophages + Met 5A group increased significantly (p < 0.05) (Table 3). The types of chromosomal aberrations are mainly breakage, chromosomal ring, triploidy, polyploidy, and so forth. Typical pictures depicting normal and aberrant chromosomes are shown in Figure 3.
Effects of resistance training on liver structure and function of aged rats
Published in The Aging Male, 2018
Ricardo Aparecido Baptista Nucci, Ana Caroline de Souza Teodoro, Walter Krause Neto, Wellington de Assis Silva, Romeu Rodrigues de Souza, Carlos Alberto Anaruma, Eliane Florencio Gama
Exercise increases oxygen consumption and reactive oxygen species (ROS) generation and, therefore, can enhance oxidative damage to nucleic acids in cells [25–28]. On the other hand, it has been well recognized that regular physical activity has health benefits such as reducing risk and progression of cardiovascular diseases, type 2 diabetes mellitus, cancer and neurodegenerative diseases [25,29–31]. Paradoxically, these diseases are suggested to be induced and exacerbated by ROS [25]. Additionally, Oliveira et al. [32] showed that animals submitted to aerobic exercise had the lower percentage of polyploids nuclei. Polyploidy results from incomplete mitotic cycles, which is tightly related to the aging process [32–34]. Our results in Figure 3 showed that the number of hepatocytes nuclei per field (NNH per field) were higher in animals submitted to RT, suggesting that exercise increase hepatocytes mitotic cycles increasing its numerical density and maintaining its area across age. These results may be related to the protective effect of regular exercise even on hepatic cells.