Repeated DNA Sequences and Polyploidy in Cereal Crops
S. K. Dutta in 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
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
The Reproductive Systems of Davidson’s Plum (Davidsonia jerseyana, Davidsonia pruriens and Davidsonia johnsonii) and the Potential for Domestication
Yasmina Sultanbawa, Fazal Sultanbawa in Australian Native Plants, 2017
Polyploidy is prominent among many cultivated crops and is possibly present in D. johnsonii, although further investigation is needed to confirm this. The importance of polyploidy in crop improvement is well recognised (reviewed by Paterson, 2005; Udall and Wendel, 2006) and often aimed for inbreeding programmes. This is because polyploidy can generate novel phenotypic variation and adaptive plasticity, both of which are beneficial traits for domestication (Olsen and Wendel, 2013). Other potential benefits of polyploidy include genome ‘buffering’ against deleterious mutations, increased allelic diversity and increased or fixed heterozygosity (Udall and Wendel, 2006). Among the many polyploid crops, the more prominent examples include sugarcane, potato, cotton, banana, wheat and strawberries.
Identification and characterization of GAL4 drivers that mark distinct cell types and regions in the Drosophila adult gut
Published in Journal of Neurogenetics, 2021
Seung Yeon Lim, Hyejin You, Jinhyeong Lee, Jaejin Lee, Yoojin Lee, Kyung-Ah Lee, Boram Kim, Ji-Hoon Lee, JiHyeon Jeong, Sooin Jang, Byoungsoo Kim, Hyungjun Choi, Gayoung Hwang, Min Sung Choi, Sung-Eun Yoon, Jae Young Kwon, Won-Jae Lee, Young-Joon Kim, Greg S. B. Suh
To identify GAL4 lines that are expressed in ECs, we selected GAL4 drivers that expressed the GFP reporter in relatively large gut cells that were positive for DAPI and negative for anti-Prospero antibody staining. The large polyploidy nuclei of ECs were clearly distinguishable with small diploid nuclei of progenitors when stained with DAPI, so the task of distinguishing ECs from other cell types was relatively straightforward. Of the 585 GAL4 lines, we identified 92 lines that were expressed in ECs in the gut; 57 were expressed only in the midgut; 25 were expressed only in the hindgut; 10 were expressed in both the midgut and hindgut (Supplementary Figure 1). Of 92 EC-expressing GAL4 lines, we found that only 10 that expressed GAL4 exclusively in ECs and not in any other cell types (Supplementary Table 3). Among those, 7 expressed GAL4 in a specific region of the gut (Figure 4(A,B)), 2 expressed GAL4 in multiple regions of the midgut (Figure 4(C)), and 1 was broadly expressed throughout the midgut (Figure 4(D)). Of the 7 lines, 2 expressed GAL4 in the R4 region, 3 expressed GAL4 in the R5 region of the midgut, and 2 expressed GAL4 in the hindgut.
EloA promotes HEL polyploidization upon PMA stimulation through enhanced ERK1/2 activity
Published in Platelets, 2022
Lanyue Hu, Weiwei Zhang, Zheng Xiang, Yali Wang, Cheng Zeng, Xiaojie Wang, Chengning Tan, Yichi Zhang, Fengjie Li, Yanni Xiao, Luping Zhou, Jiuxuan Li, Chun Wu, Yang Xiang, Lixin Xiang, Xiaomei Zhang, Xueying Wang, Wuchen Yang, Maoshan Chen, Qian Ran, Zhongjun Li, Li Chen
MKs are unique non-pathological polyploid cell in mammals that possess the role of assembling and releasing platelets. Polyploidization enlarges the size of MKs and makes the MKs more efficient on the production of mRNAs and proteins, which is an economic and efficient process for platelet production. Exploring the regulation mechanism of MK polyploidization is of great practical significance for the efficient preparation of platelets. However, the mechanism of polyploidy in MKs has not been fully elucidated. Transcriptional regulation has been shown to be involved in the MK polyploidization; however, previous studies on transcription regulation of MKs focused on the regulation of transcription factors. RUNX1-mediated silencing of MYH10 contributes to the MK polyploidization [6]. GATA-1 is essential for the MK differentiation pathway and controls the polyploidization by regulating the cyclin D-Cdk4 kinase activity [7]. Transcription factors and transcription elongation factors play important roles in the complex transcription process in eukaryotes. Although significant progress has been made in terms of transcription factors, transcription elongation factors governing the complex process are far from clear. In the present study, the regulatory mechanism of transcription elongation factor in MK polyploid formation was expounded for the first time. This study provides a solid basis for a comprehensive understanding of the transcriptional regulatory mechanisms of MKs.
CDKN2A Depletion Causes Aneuploidy and Enhances Cell Proliferation in Non-Immortalized Normal Human Cells
Published in Cancer Investigation, 2018
Zofia Hélias-Rodzewicz, Nelson Lourenco, Mariama Bakari, Claude Capron, Jean-François Emile
Analysis of metaphase spreads was performed in seven-day interval silencing experiments and revealed that the inhibition of each candidate gene induced aneuploidy. The number of abnormal metaphases was higher in candidate genes siRNA-treated cells than in the controls. These findings were similar for both cell lines (Figure 1(A,B)) (p < 0.05). For each experimental condition, at least 50 metaphases were analyzed, except for some CDCA8, CCNDBP1, and TP53BP1 experiments. For CHEK2, CCNDBP1, TP53BP1, and CDKN2A, these chromosome instability results were confirmed in 21-day experiments (Figure 1(C)). The most common chromosome alterations were losses of 1 or 2 chromosomes (Figure S4). In IMR-90 cells, the presence of aneuploidy after candidate gene silencing was validated by fluorescence in situ hybridization (FISH) with centromere probes for four different chromosomes (chromosomes 6, 12, 16, 17) (Figure 1(D), Figure S5). FISH also showed that silencing the expression of the candidate genes did not induce polyploidy (Figure 1(E)).
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