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Evolutionary computation
Published in Richard E. Neapolitan, Xia Jiang, Artificial Intelligence, 2018
Richard E. Neapolitan, Xia Jiang
An organism is an individual form of life such as a plant or animal. A cell is the basic structural and functional unit of an organism. Chromosomes are the carriers of biologically expressed hereditary characteristics. A genome is a complete set of chromosomes in an organism. The human genome contains 23 chromosomes. A haploid cell contains one genome; that is, it contains one set of chromosomes. So a human haploid cell contains 23 chromosomes. A diploid cell contains two genomes; that is, it contains two sets of chromosomes. Each chromosome in one set is matched with a chromosome in the other set. This pair of chromosomes is called a homologous pair. Each chromosome in the pair is called a homolog. So a human diploid cell contains 2 × 23 = 46 chromosomes. One homolog comes from each parent.
Illuminating the cycle of life
Published in Raquel Seruca, Jasjit S. Suri, João M. Sanches, Fluorescence Imaging and Biological Quantification, 2017
Anabela Ferro, Patrícia Carneiro, Maria Sofia Fernandes, Tânia Mestre, Ivan Sahumbaiev, João M. Sanches, Raquel Seruca
The DNA content and its variation during the cell-cycle phase is a specific signature of each biological sample. Briefly, during the cell cycle, nondividing eukaryotic cells remain quiescent by entering the G0 state; these are diploid cells, possessing two sets of chromosomes (2N). On reentering the cell cycle, these diploid cells start growing while progressing through G1 phase. In normal conditions, cells then proceed to an intermediate phase of synthesis (S phase) during which DNA and protein content is duplicated. On completion of this phase, cells are at G2 phase and are tetraploid (4N). At this point, mitosis (M phase) ensues and cells split in two new diploid daughter cells. Depending on their DNA content, cells may be categorized in three major classes of the cell cycle: (1) prereplicative for G0/G1 phase cells, (2) replicative for S phase cells, or (3) postreplicative and mitotic cells during G2/M phase [13]. As cells’ cycle through each division, the surveillance of the fidelity of this process is fundamental, and the determination of DNA content during the cell cycle of individual or subpopulations of cells may highlight important biological cues on their physiological status [8]. The possibility to measure rapidly and accurately the DNA content of individual cells from large cell populations is harnessed to the evolution of cytometry-based methodologies and their applications in different cell types. In this chapter, we dissect the most widely used methods of DNA content analysis applied to cell-cycle analysis, as well as, the up-to-date cell-based fluorescent methodologies that are highly impacting on cell-cycle profiling.
Introduction to Cancer, Conventional Therapies, and Bionano-Based Advanced Anticancer Strategies
Published in D. Sakthi Kumar, Aswathy Ravindran Girija, Bionanotechnology in Cancer, 2023
The genetic theory of carcinogenesis is the most common theory. It states that normal cells become neoplastic due to mutations in the DNA [21]. The gene mutation theory predicts the spontaneous appearance of diploid polyclonal cancer cells following the accumulation of a sufficient number of transforming genes. The oncogenes of retroviruses are a class of genes that meet the predictions of the gene mutation theory because transformation takes place within one or limited cell generations, and the transformation depends on the continued role of viral proteins. Furthermore, the tumors seem to be diploid, or at least at the beginning [22].
Absolute telomere length in peripheral blood lymphocytes of workers exposed to construction environment
Published in International Journal of Environmental Health Research, 2023
Paula Rohr, Isabela Campanelli dos Santos, André van Helvoort Lengert, Marcos Alves de Lima, Rui Manuel Reis, Fernando Barbosa, Henrique Cesar Santejo Silveira
DNA was isolated using a QIAsymphony SP DSP DNA Mini Kit on QIAsymphony SP platform (Qiagen, Hilden, Germany) according to the manufacturer’s instructions. The extracted DNA was quantified by spectrophotometry using a NanoDrop 2000c (ND-1000 Spectrophotometer v.3.0.1; Thermo Fisher Scientific, Waltham, MA, USA) and diluted to 5 ng/μL. The absolute TL was measured by quantitative polymerase chain reaction (qPCR) according to O’Callaghan (2011) (O’Callaghan and Fenech 2011). Briefly, we performed two standard curves by the dilution of known quantities of a synthesized oligonucleotide representing the telomere (TEL STD) and 36B4 (36B4 STD), a single-copy gene, used to measure diploid genome copies per sample. The reactions were performed containing 1x PowerUp™ SYBR™ Green Master Mix (Thermo Fisher Scientific), Primer forward 0.02 µM, Primer reverse 0.02 µM, 20 ng DNA and distilled water for final volumes of 20 µL per reaction. The qPCR was performed under the following conditions (for both telomere and 36B4 amplicons): Taq polymerase activation for 10 min at 95°C followed by 40 cycles of denaturation at 95°C for 15 s, annealing and extension at 60°C for 1 min, followed by melting curve.
Consolidated bioprocessing for cellulosic ethanol conversion by cellulase–xylanase cell-surfaced yeast consortium
Published in Preparative Biochemistry and Biotechnology, 2018
Le Chen, Ji-Liang Du, Yong-Jia Zhan, Jian-An Li, Ran-Ran Zuo, Shen Tian
The recombinant S. cerevisiae strains used in the present work were summarized in Table 1. Xylose-utilizing recombinant S. cerevisiae Y5 (a flocculent diploid yeast strain developed in our laboratory) was the host cell for cell-surface displaying cellulases and xylanase. Xylose reductase (XR, X1), xylitol dehydrogenase (XDH, X2) and xylulokinase (XKS, X3) were obtained in our previously work.[20]Escherichia coli Top10 (Tiangen Biotech Co., Ltd., Beijing, China) was used for genetic manipulations. T. reesei 40358, A. aculeatus 41132 and A. oryzae 2120 were purchased from CICC. Transformants of recombinant S. cerevisiae were selected and grown on synthetic dropout plate medium (SD) with amino acids as required. Cell cultures of E. coli were maintained in Luria–Bertani medium (0.5% yeast extract, 1% tryptone, 1% NaCl) supplemented with 100 μg/mL of ampicillin.[21]T. reesei, A. aculeatus, and A. oryzae were grown on PDA medium.
Ozonated Olive Oil with a High Peroxide Value for Topical Applications: In-Vitro Cytotoxicity Analysis with L929 Cells
Published in Ozone: Science & Engineering, 2018
Yasemin Günaydın, Handan Sevim, Deniz Tanyolaç, Özer A. Gürpınar
The evaluation of cytotoxic and cytostatic effects of a chemical compound is very important in order to determine the first risk assessment when working witih new biomaterials. Most current tests include the level of cell viability assays after exposure to a chemical compound or a biomaterial. Many cell culture techniques are used to assess cell damage caused by biomaterials. These methods are based on cell cultures with established or diploid cell lines and primary tissue explants techniques (Can et al. 2010). In the present study, morphological observation of L929 cells was initially performed under an inverted microscope. Control cells and OZ-Oo-treated cells showed a flattened fibroblastic morphology; however, the cells incubated with OZ-Gly showed visible changes in morphology such as an elongated and rounded shape (Figures 3a–3c). These morphological observations were consistent with the MTT results.