China 
Africa 
Explore chapters and articles related to this topic
The Emergence of Order in Space
Published in Pier Luigi Gentili, Untangling Complex Systems, 2018
The mechanochemical patterning is responsible for cell polarity (Goehring and Grill 2013). Cell polarity is the asymmetric organization of a cell. Cell polarity is crucial for certain cellular functions, such as cell migration, directional cell growth, and asymmetric cell division. It is also relevant in the formation of tissues. For example, epithelial cells are examples of polarized cells that feature distinct apical and basal plasma membrane domains (see Figure 9.14). The apical-basal polarity drives the opposing surfaces of the cell to acquire distinct functions and chemical components. There is also planar cell polarity that aligns cells and cellular structures such as hairs and bristles within the epithelial plane. Cell polarity is so fundamental that it is ubiquitous among living beings: it is present not only in animals and plants, but also in fungi, prokaryotes, protozoa, and even archaebacteria.
It's not just about protein turnover: the role of ribosomal biogenesis and satellite cells in the regulation of skeletal muscle hypertrophy
Published in European Journal of Sport Science, 2019
Matthew Stewart Brook, Daniel James Wilkinson, Ken Smith, Philip James Atherton
Skeletal muscles cells are multinucleated but terminally differentiated cells (Heron & Richmond, 1993). However, skeletal muscle also possess a residual pool of resident muscle stem cells – SC (Mauro, 1961). Unlike their sub-sarcolemma Myonuclei counterparts, SC are located in the extracellular matrix between the sarcolemma and the basal lamina and in being a type of stem cell (unlike myonuclei) (Bintliff & Walker, 1960), SC possess mitotic potential. The physiological role of SC is thought to be the provision of “new” nuclei to existing myofibers, supporting transcriptional capacity, while at the same time ensuring through division, sustainment of an extracellular SC population. Upon activation, SC exist quiescence and enter the cell cycle where they can proliferate as myoblasts and potentially terminally differentiate. A population of these cells will undergo asymmetric cell division where by one daughter cell remains quiescent maintaining SC number and a continued source of myonuclei (Moss & Leblond, 1971; Troy et al., 2012). The contended role of SC in the regulation of hypertrophy was derived from the concept that each nuclei of a multi-nucleated myofibre appears to synthesise protein for a close vicinity domain (Figure 2) (Gundersen, Sanes, & Merlie, 1993; Hall & Ralston, 1989) and that this karyoplasmatic ratio is held constant (Allen, Roy, & Edgerton, 1999). Obviously, this means that as a muscle hypertrophies, the fixed nuclei content of terminally differentiated muscle cells essentially becomes “diluted” to a point that a new source of nuclei is needed to support the transcriptional requirements of supporting a larger myofiber volume. Therefore, the potential role for SC in regulating and/or limiting muscle hypertrophy has many foundations that warrant detailed consideration.