Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Totipotency differentiation

All secondary cell walls develop from primary cell walls. Cells no longer grow once lignin is added to their wails. Lignification, which is a key step in the conversion of a primary cell wall into a secondary cell wall, results in terminal differentiation of the encased cell. Indeed, many cells with lignified walls die. The totipotency of plant cells is limited to cells enveloped in primary walls. [Pg.47]

As an alternative to adult stem cells, embryonic stem cells can be used. These are totipotent and can be obtained from the internal blastocyst cell mass. Because of the capacity of these cells to generate any type of functional cell, their manipulation and differentiation have gained in significance. In spite of recent advances (Daley, 2003 Hwang et al., 2004), knowledge on the control of their differentiation and proliferation is still lacking, but will be necessary to make the exploitation of all their therapeutic potential turn into reality. Further discussion on cell therapy can be found in Chapter 20. [Pg.7]

Well, it s only human nature to ask, If sea anemones can clone themselves without hardly trying, and the natural cloning powers of plants are so easily exploited, why can t we begin learning how to clone ourselves The answer to that question is hidden in the secrets of the cell. All plants have one kind of cell that remains forever in the embryonic condition. These cell layers of embryonic tissue are totipotent and can give rise to new differentiated cells. Cut the stem of a plant and these cells will produce root, stem, and leaf tissues. In some animals, totipotent cells—as in the foot of a sea anemone—when cut, will dedifferentiate, and return to an embryonic condition. Then they... [Pg.10]

Stem cells. Embryonic and adult stem cells are distinguished. Embryonic stem cells are taken from an early stage of the embryo, such as from blastocytes. They are undifferentiated and totipotent. Their potential to differentiate and to form different cell lines is unlimited. Adult stemcells are taken from the blood forming bone marrow, from epithelial cells from the skin and other sources. They are pluripotent. Both, embryonic totipotent and adult pluripotent stem cells can replace functionally differentiated cells and tissues in the body. Stem cells can divide. After division, they may form again a stem cell or proceed to a final, fully differentiated state. [Pg.320]

Embryonic Germ Cells (EGC) Primordial germ cells of 5-to 9-week fetuses Infinite Totipotent (Can differentiate into every cell of the organism)... [Pg.152]

Illmensee, K., and Mintz, B. (1976). Totipotency and normal differentiation of single teratocarcinoma cells cloned by injection into blastocysts. Proc Natl Acad Sci USA 73(2), 549-553. [Pg.160]

Another aspect of LIF was revealed by studies on the activity that prevents differentiation of totipotent ES cells derived from normal blastocysts (Williams et al., 1988 Smith et al., 1988 Gough et al., 1989 Smith et al., 1992). It is known that to maintain the totipotency of ES cells, they must be grown on a feeder layer of fibroblasts. The activity secreted by the feeder layer fibroblasts, termed DIA (differentiation inhibitory activity) or DRF (differentiation retarding factor), has been purified, and its characteristics suggest that DIA/DRF may be identical to LIF. Indeed, not only does LIF exhibit the same activities as DIA and DRF in vitro, but also ES cells cultured with LIF can retain their totipotency. When the ES cells treated with LIF are injected into mouse blastocysts and then introduced into pseudo-pregnant females, they contribute extensively to the development of all of the somatic tissues (Williams et al., 1988 Gough et al., 1989). [Pg.266]

ES cells should be cultured on a feeder layer of inactivated embryonic fibroblasts (Robertson, 1987). Embryonic fibroblasts should be used within a week after inactivation. The ES cells should be split every second day (see below). It is important that the ES cells be trypsinized to obtain a single cell suspension to avoid differentiation. Totipotency in ES cells tends to be lost with passage number it is therefore advisable to subclone the cells each 20 passages to recover the full potentiality. [Pg.114]


See other pages where Totipotency differentiation is mentioned: [Pg.307]    [Pg.307]    [Pg.120]    [Pg.99]    [Pg.602]    [Pg.1886]    [Pg.1886]    [Pg.807]    [Pg.905]    [Pg.150]    [Pg.108]    [Pg.284]    [Pg.774]    [Pg.774]    [Pg.2665]    [Pg.336]    [Pg.130]    [Pg.132]    [Pg.626]    [Pg.1979]    [Pg.1980]    [Pg.901]    [Pg.952]    [Pg.535]    [Pg.1332]    [Pg.81]    [Pg.28]    [Pg.505]    [Pg.509]    [Pg.624]    [Pg.126]    [Pg.308]    [Pg.311]    [Pg.95]    [Pg.874]    [Pg.180]    [Pg.181]    [Pg.160]    [Pg.290]    [Pg.240]    [Pg.380]    [Pg.172]   
See also in sourсe #XX -- [ Pg.149 ]




SEARCH



Totipotency

© 2024 chempedia.info