Cell cultures organogenesis

Figure 97. Cell-culture techniques in the organogenesis stage. Arrows indicate medium. (Photo T. Aniszewski)...

Fig. 25.3 The pathways that can be taken in the development of plant tissue and cell cultures starting from a part of a plant (explant). The explant can via direct embryogenesis or oganogenesis form embryos or shoot and roots, respectively, which can be converted into plants. In another path, the explant can form a callus, which can then be used to form a suspension culture. In addition, indirect organogenesis or embryogenesis of the callus can lead to plant formation...

Organogenesis In animal cell cultures, the evolution, from dissociated cells, of a structure that shows natural organ form or function or both. In plant tissue culture, a process of differentiation by which plant organs are formed de novo or from pre-existing structures. In developmental biology, this term refers to differentiation of an organ system from stem or precursor cells. 

FIGURE 6.8 Cell-culture technigues in the organogenesis stage. 385... 

The micromass culture is making use of cell cultures of the limb bud and/or neuronal cells. The cells are isolated from the limb or the cephahc tissues of mid-organogenesis embryos (Whittaker and Faustman, 1994). After preparing a single cell solution, the cells... 

Figure 9-5 The sensitivity of the conceptus to a theoretical teratogen during rat gestation (modified from 161). The most susceptible window is organogenesis with low levels of vulnerability at the time of implantation and the period of functional maturation. Superimposed are the approximations of when the developmental landmarks that are represented in the four in vitro tests occur. The chick embryo neural retina model (CENR) represents events around GD 10-13. The mouse embryonic stem cell test (EST) corresponds roughly to the period of GD 6-10 in the rat, near the peak of sensitivity. Whole embryo culture (WEC) recapitulates the window at the peak of sensitivity, between GD 9-11 or GD 10-12 depending upon the window within which the culture is conducted. Rabbit cultures are also done between GD 10-12. Represented by the single ( ) and double asterisk ( ), respectively, are the initiation and termination of the dosing period in regulatory compliant preclinical embryo/fetal toxicity studies. Thus, the zebrafish is the only model that permits exposure to test article during this important period.

Auxins and cytokinins are the most widely studied plant hormones on account of their importance for cell growth and division and, from a practical point of view, for their profound impact on organogenesis when plant cells and tissues are cultured in vitro. Not surprisingly, therefore, both these hormones were included in pioneering studies of hormonal effects on the orientation of MTs in relation to cell growth (e.g. references... 

Thorpe, T.A. (1980). Organogenesis in vitro structural, physiological and biochemical aspects. In Perspectives in plant cell and tissue culture. International Review of Cytology - Supplement llA, Vasil, I.K (Ed.), pp. 71-111, ISSN 0074-770X New York... 

Cytokinins are potent morphogenetic substances known to regulate organogenesis in cultured tissues (92). Studies of cytokinin habituation suggest that cell heritable states of cytokinin requirement are maintained by a regulatory positive-feedback... 

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