Parental cell

Yeasts are one land of fungi. They are unicellular organisms surrounded by a cell wall and possessing a distinct nucleus. With veiy few exceptions, yeasts reproduce by a process known as budding, where a small new cell is pincEed off the parent cell. Under certain conditions, an individual yeast cell may become a fruiting body, producing spores. 

Binary fission During binary fission, a single cell divides transversely to form two new cells called daughter cells. Both daughter cells contain an exact copy of th geneticinformation contained in the parent cell. 

Mutter-kraut, n. feverfew, -kuchen, m. placenta, -kummel, m. cumin, -lauge, /. mother liquor, -leib, m. womb, uterus, -neike, /. mother clove, -pech, n. Med.) meeonium. -pflanze, /, parent plant, -scheibe, /. Mach.) nut washer, -schliissel, m. nut wrench, -sicherung, /. Mach.) nut lock, -stoff, m, -substanz, /, mother substance, parent substance matrix, -ver-schluss, m. Mach.) nut lock, -zelle, /. mother cell, parent cell, -zimt, m. cassia. Mutung,/. claim, demand, concession. 

In parental cells, pelDv.uidA expression in IP decreased when previously supplemented with PeCl3. In cbsE-I cells, expression of pelDv.uidA was higher than in parental cells and addition of PeCl3 into IP was ineffective. 

A strain is a pure culture containing only the descendants of a single parent cell since there is no standardized system for giving numbers to strains, each laboratory uses its own system. Many strains of bacteria are maintained for study in international culture collections but some bacteria have not yet been grown in the absence of other organisms. 

By definition, cell mitosis results in two daughter cells, identical to each other and to the parent cell. So in order to break symmetry, bit 1 in the state vector is set to 1 in one cell, while it is set to the reverse (0) in the other cell. The first 3 bits of the state vector are prespecified as the ones indicating cell type — in reverse. For example, a cell with state vector = 001110 has type 001-reversed, which is 100 or 4 (in decimal). This entails that the first division inevitably results in two cells of different types with state vectors 000100 and 100100, respectively. 

Monoclonal antibodies are antibodies that are identical because they were produced by immune cells that all are clones of a single parent cell. 

Accumulation/efflux studies can be performed on different cell systems or membrane vesicle preparations. In the accumulation assays, uptake of a probe over time, typically either fluorescent (e.g. calcein-AM (CAM) [25-27]) or radiolabeled, into the cell or membrane vesicles is measured in the presence or absence of a known P-gp inhibitor. As P-gp transports substrates out of the cells, the inhibition of the protein would result in an increase in the amount of the probe in the cell. Accumulation studies in cells that overexpress P-gp can be compared to those obtained in the parental cell line that does not have as high a level of P-gp expression. The probe in the absence of inhibitors shows lower accumulation in P-gp expressing cells than in P-gp deficient cells. Similarly, probe accumulation is increased under conditions where P-gp is inhibited such that the difference in accumulation in P-gp deficient and overexpressing cells, respectively, becomes smaller. Accumulation assays poorly distinguish substrates and inhibitors of P-gp and, as far as transport assays are concerned, are also influenced by a passive diffusion property of molecules [20]. In contrast to transport assays, both accumulation (i.e. calcein-AM assay) and ATPase assays tend to fail in the identification ofrelatively low permeable compounds as P-gp active compounds [20]. 

DNA is the carrier of the genetic information of all cells and many viruses. Two important points follow from this simple statement. First, DNA must be replicated in order for cell division to take place, hi cell division, one cell becomes two and each must have its own store of genetic information. The genetic information is stored in chromosomes and each chromosome contains a single molecule of DNA. Secondly, the replication of DNA must be a very precisely controlled process. The goal is for each daughter cell to have exactly the same genetic information as the parent cell, which requires that each chromosomal DNA molecule replicated in the course of... 

Meiosis is cell division that produces two daughter cells with only half the number of chromosomes of the parent cell these are haploid cells. It occurs during the formation of spermatozoa and ova. The normal number of chromosomes is then achieved at fertilisation of an ovum by a spermatozoon. Meiosis also results in crossing over , which is the physical reciprocal exchange of parts... 

It is essential that, in mitolic cell division, genetic information in the parent ceU, which is encoded in the base sequence of its DNA, is copied exactly so that each daughter cell receives genetic information identical to its parent cell. Consequently, before a ceU divides, its DNA must have been replicated completely and accurately. The... 

Oncogene-transformed mouse fibroblasts have a more decondensed chromatin structure than parental cell lines [59]. Phosphorylated Hl -3 levels are elevated in oncogene (ras, raf, fes, mos, myc) and aberrantly expressed MAPKK (MEK) transformed mouse fibroblasts, which have elevated activities of MAPK (ERKl and 2) [59] (Fig. 6). Further, RZ)-deficient human fibroblasts have increased levels of phosphorylated HI and a relaxed chromatin structure [60]. Cyclin E-Cdk2 was directly involved in increasing the levels of phosphorylated HI [60]. Elevated cyclin E-Cdk2 activity resulting from persistent activation of the Ras-MAPK pathway is also responsible for increased level of phosphorylated HI in oncogene-transformed mouse fibroblasts [61]. 

Endogenous microbial enzymes are sometimes utilized to break down their parent cells, and thus extract valuable intracellular materials. For instance, in the production of yeast extract, cells are allowed to autolyse at about pH 5 and 55 0. Proteases are probably the most important class of enzymes involved in autolysis, although others such as glucanases, lipases and nucleases also have... 

Cells that exhibit high (several hundredfold) levels of resistance to vinblastine, vincristine, and vindesine have an extremely limited capacity to accumulate radiolabeled vinblastine for example, essentially no increase in radioactivity associated with human leukemic lymphoblastic cells resistant to vinblastine could be detected over a 60-min incubation period in the presence of concentrations of tritiated vinblastine that were cytotoxic to parent cells. The parent cells, highly sensitive to vinblastine, were observed to accumulate vinblastine to levels seven-fold higher than those observed for the resistant cells (76). 

Fine et al. described that the activity of PKC was 7-fold higher in multidrug resistant cells compared with the sensitive parental breast cancer cells (Fine et al., 1988). An over 6-fold increase in PKC activity in the MDR human breast cancer subline MCF-7/DOXR was confirmed vdien compared with the sensitive parent cell line, MCF-7AVT (Schwartz et al., 1991). Aquino et al. found that multidrug resistant HL-60/ADR cells contained 2-fold more PKC than the parental cell line (Aquino et al., 1988). In four murine UV-2237M... 

Once the Tet-repressor clone has been obtained, it is helpful to compare its proliferation rate with the parental cell line to ensure a comparable duplication time. This will allow for a reliable comparison of data to that obtained from already performed drug treatments on the parental line or for the compliance with standardized protocols. 

Pretest shRNA activity to validate its efficacy by assessing target modulation through a transient transfection (see Note 17) in cells lacking the repressor (parental cell line) or in a TetR clone in the presence of doxycycline (see Note 18). 

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