The DNA is similar in every cell of the body, but depending on the specific cell type, some genes may be turned on or off - that's why a liver cell is different from a muscle cell, and a muscle cell is different from a fat cell. The DNA stores the organism’s entire encoded genetic information. Genes within the chromatin are made of deoxyribonucleic acid (DNA).
The chromatin is efficiently packaged within the small nuclear space. Within each nucleus is nuclear chromatin that contains the organism’s genome. It is enclosed in a double membrane and communicates with the surrounding cytosol via numerous nuclear pores. In sum, S-cells may represent a newly identified developmental stage that enables actinomycetes to thrive under hyperosmotic stress conditions.Nucleus: The nucleus is the most obvious organelle in any eukaryotic cell. Finally, following prolonged exposure to osmotic stress, some cells acquire mutations and convert into L-forms that can proliferate indefinitely in the cell wall-deficient state. This cell wall-deficient state is transient as S-cells can switch to the canonical mycelial growth mode, although those switched colonies exhibit developmental defects. S-cells extrude from the hyphal tips into the environment, contain DNA and are larger than 2 µm in size (distinguishing them from spores). Formation of S-cells seems to be common in filamentous bacteria, as they occur in Streptomyces and Kitasatospora species in response to hyperosmotic stress. Claessen and colleagues now report that when filamentous actinomycetes are exposed to osmotic stress they extrude previously undetected cell wall-deficient cells, which they termed S-cells. Bacterial variants that lack a cell wall are known as L-forms and can be induced under conditions that interfere with cell wall synthesis.
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