How can polarization of a cell be reduced
Answers
Explanation:
Cell polarization is a key step in the migration, development, and organization of eukaryotic cells, both at the single cell and multicellular level. Research on the mechanisms that give rise to polarization of a given cell, and organization of polarity within a tissue has led to new understanding across cellular and developmental biology. In this review, we describe some of the history of theoretical and experimental aspects of the field, as well as some interesting questions and challenges for the future.
Introduction
Specifying an axis of directionality is essential for most living cells. In the repertoire of cells that move individually, including Dictyostelium amoebae, neutrophils, keratocytes, and fibroblasts, determining the cell front and back is a prerequisite for organizing the machinery that powers cell motility (Fig. 1A). This includes the actin cytoskeleton, myosin, and, in some cases, microtubules. In organized cell collectives such as epithelia, the apical and basal faces of individual cells are distinct from one another and from the lateral surfaces along which cell-cell contact is maintained (Fig. 1B). Even in plant cells, whose shapes are constrained by rigid cell walls, the axis of polarity forms with growth, and is essential for defining cell division planes, and hence, organizing the shape of the plant tissue that emerges
Biological observations that motivated cell polarity research
Early observations of single cells using conventional microscopy defined polarization according to cell shapes with elongated cells being more polarized than round cells. For moving cells, the migration direction is typically in the direction of the polarity axis, defined as the long-axis of the cell. Although these observations were instructive, they did not provide any data about the intracellular distributions of signaling components. This information has become available, however, due to advances in microscopy, and in particular fluorescence microscopy. Immunostaining, for example, allows the visualization of proteins in fixed cells, thus enabling the quantification of asymmetries in intracellular and membrane localizations. Even more informative, however, are methods that fuse signaling components to fluorescent probes, enabling the dynamic visualization of their spatio-temporal distribution.
These experiments have revealed that many signaling components are roughly uniformly distributed within the cytosol in unpolarized cells but have a pronounced asymmetric distribution in polarized cells. In moving cells, for example, the front is associated with high concentrations of actin while the back displays elevated myosin concentrations [25]. Other non-cytoskeleton components that show distinct localization during polarization include the phosphatidylinositol lipid PIP3 (front), along with its phosphatase and kinase (PTEN, back, and PI3K, front) [26,27]. In addition, many small GTPases display asymmetric distributions within a polarized cell. In budding yeast, Cdc42 localizes to the budding site, while in neutrophils and other migrating mammalian cells, Cdc42 is found at the front and Rho is found primarily at the back of the cell [28,29]. These distributions can be measured with high temporal and spatial precision, even under changing conditions. The emergence of such quantitative data has resulted in a surge of interest in the development of models for cell polarity establishment and maintenance, as described below.
please mark me as brainliast please please ......................
Explanation:
ndjdndndndndndn ndjdndndndndndn ndjdndndndndndn ndjdndndndndndn m n o p n n o p q r mtktktmtmtktktmtmt