In general, the process of cell differentiation is irreversible. However, under certain conditions, the differentiated cells are also unstable, and their gene expression patterns can also undergo reversible changes and return to their undifferentiated state. This process is called dedifferentiation.
Features of cell differentiation include: The potential of differentiation gradually appears with the development of the individual. During embryonic development, the cells gradually change from "all-around" to "multi-energy", and finally to the "single-energy", which is the general rule of cell differentiation.
In the process of individual development, multicellular biological cells have both temporal differentiation and spatial differentiation; cell differentiation is compatible with the state and speed of cell division, and differentiation must be based on division, that is, differentiation is inevitable with division, but the dividing cells do not necessarily need differentiate.
The higher the degree of differentiation, the worse the ability to divide; the cell differentiation is highly stable. Under normal physiological conditions, cells that have differentiated into a specific, stable type are generally impossible to reverse to undifferentiated state or become other types. Cell differentiation is plastic, and the differentiated cells re-enter the undifferentiated state or transdifferentiate into another type of cell under special conditions. Embryonic stem cells ES cells have the potential to develop into different types of cells.
Under suitable conditions in vitro , they can proliferate in an undifferentiated state, providing a source of cells for the research and application of ES cells. The mouse embryonic stem cells treated with retinoic acid will differentiate into neural progenitor cells and then treat with Shh specific small molecule antagonist Hh-Ag 1. Takahashi et al found that ascorbic acid can effectively enhance the differentiation of embryonic stem cells into cardiomyocytes.
Wu et al. Hironori et al. Of course, due to the existence of immunocompatibility issues, the safety of embryonic stem cell transplantation needs to be a comprehensive, objective and in-depth evaluation. Bone marrow stromal cells MSCs are derived from mesoderm and can differentiate into mesoderm cells such as osteoblasts, chondrocytes, myoblasts, tendon cells, adipocytes, and stromal cells under certain induction conditions; it can differentiate into neuroblast cells of the ectoderm and hepatic oval cells of the endoderm.
Due to its wide source of materials and the low degree of immune rejection during transplantation, it is a target cell for cell replacement therapy with the good clinical application. Many research groups conducted in vitro differentiation experiments of MSCs under in vitro culture conditions.
Woodbury et al. Deng et al. MSCs can differentiate into osteoblasts under the induction of dexamethasone, sodium 8-glycerophosphate and vitamin C. Dexamethasone can regulate gene expression in differentiated cells and promote the transformation into osteoblasts by enhancing the affinity of its receptors to genomic target sequences.
These junctions are reinforced by attachment to an extensive array of actin filaments that underlie the apical — or lumen-facing — membrane. These organized collections of actin filaments also extend into the microvilli , which are the tiny fingerlike projections that protrude from the apical membrane into the gut lumen and increase the surface area available for nutrient absorption.
Additional mechanical support comes from desmosomes , which appear as plaque-like structures under the cell membrane, attached to intermediate filaments. In fact, desmosome-intermediate filament networks extend across multiple cells, giving the endothelium sheetlike properties.
In addition, within the gut there are stem cells that guarantee a steady supply of new cells that contribute to the multiple cell types necessary for this complex structure to function properly Figure 2. The extracellular matrix ECM is also critical to tissue structure, because it provides attachment sites for cells and relays information about the spatial position of a cell.
The ECM consists of a mixture of proteins and polysaccharides produced by the endoplasmic reticula and Golgi apparatuses of nearby cells. Once synthesized, these molecules move to the appropriate side of the cell — such as the basal or apical face — where they are secreted. Final organization of the ECM then takes place outside the cell.
To understand how the ECM works, consider the two very different sides of the gut endothelium. One side of this tissue faces the lumen, where it comes in contact with digested food. The other side attaches to a specialized ECM support structure called the basal lamina.
The basal lamina is composed of collagen and laminin proteins, as well as various other macromolecules. On this side of the endothelium, adhesive junctions attach cells to the ECM. Transmembrane integrin proteins in the junctions bind components of the ECM and recruit signaling proteins to their cytoplasmic sides.
From there, the signals travel to the nucleus of each cell. This page appears in the following eBook. Aa Aa Aa. Cell Differentiation and Tissue. The gut contains a mixture of differentiated cells and stem cells. Figure Detail. Tissues are communities of cells that have functions beyond what any single cell type could accomplish. Healthy tissues require the proper mix of cells, and the cells within them must be oriented correctly and dividing at an appropriate rate.
In order to coordinate their function, organization, and rates of death and division, the cells in a tissue are constantly processing and responding to signals from one another and from the ECM around them. Cell Biology for Seminars, Unit 5. Topic rooms within Cell Biology Close. No topic rooms are there. Or Browse Visually. Student Voices. Creature Cast. Simply Science. Green Screen. Green Science. Bio 2. The Success Code. Why Science Matters. Also, they undergo unique metabolic reactions inside the cell.
As a result, different cells become specialized to perform different functions in the body of a multicellular organism. Figure 2: Cell Differentiation. The cells with similar functions occur in groups called tissues.
Therefore, a particular tissue contains morphologically similar cells with the same function. Therefore, in order to perform each function of the body, there is a specialized type of tissue. Cell determination refers to the process of selection of portions of the genome for gene expression in different embryonic cells.
While, cell differentiation refers to the process of specialization of a cell to make it perform a specific function. Thus, this explains the main difference between cell determination and cell differentiation. Another difference between cell determination and cell differentiation is that the cell determination occurs in totipotent, embryonic stem cells while the cell differentiation follows cell determination. Moreover, the asymmetric segregation of cytoplasmic determinants results in cell determination while differential gene expression results in cell differentiation.
Also, cell determination is responsible for assigning the fate of the cells while cell differentiation is responsible for the functional specialization of the cells. Hence, this is another difference between cell determination and cell differentiation. Cell determination is a result of the asymmetric segregation of cytoplasmic determinants, which leads to the selection of the genes to be expressed.
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