Yeast budding characteristics

Yeasts exhibit several types of budding which may be of diagnostic value. Among those isolated from fermenting and aging wine, multilateral (characteristic of Saccharomyces sp.) and restricted polar budding (characteristic of apiculate yeasts) are most frequendy observed. Occassionally, fission yeasts Schizosaccharomyces pombe) may be isolated. These reproduce by the formation of cross-walls which is visually similar to bacterial fission. 

Multilateral Budding. Characteristic of Saccharomyces sp., multilateral budding occurs on the shoulder area of the yeast. Each bud arises at a location separate from others. As seen in the electron micrograph (Fig. 3-4), (not visible using a standard compound microscope), upon separa-... 

Several lines of evidence indicate that MPF-catalyzed phosphorylation also plays a role in chromosome condensation and formation of the mitotic spindle apparatus. For instance, genetic experiments in the budding yeast S. cerevisiae identified a family of SMC (structural maintenance of chromosomes) proteins that are required for normal chromosome segregation. These large proteins (-1200 amino acids) contain characteristic ATPase domains at their C-termlnus and long regions predicted to participate in colled-coll structures. 

Rabitz et al. in their first articles assumed (Reuven et al. 1986 Smooke et al. 1988 Rabitz and Smooke 1988 Vajda et al. 1990 Vajda and Rabitz 1992 Mishra et al. 1994) that the similarity of sensitivity functimis is characteristic for flame models. Zsely et al. (Zsely and Turmyi 2003 Zsely et al. 2003, 2005 Zador et al. 2004) also found the similarity of sensitivity functions for models of homogeneous explosions for several chemical systems. More recently, the similarity of sensitivity functions was detected in several biological models. Lovrics et al. (2008), for example, found such similarities in the Chen et al. (2000) model of the cell cycle of budding yeast. Danis and Turanyi (2011) found such similarities in the Rao et al. (2004) model of the chemotaxis of bacteria E. coli and B. subtilis. In the following, the results of Lovrics et al. wiU be discussed in detail. 

These data suggest that derepression is not dependent on the budding pattern characteristic of the normal cell division cycle in yeast.The question then arises whether it depends in any way on other aspects of the cycle. In the experiment just described, there is virtually no increase in cell number and no increase in cell protein, while cellular dry-weight in the culture is increased from 15.2 mg/ml to 19.1 mg/ml during the first 2 h, and then increased gradually to 23.4 mg/ml by the end of the run. The possibility must, therefore, be entertained that derepression might still depend on an early cell cycle parameter, such as the initiation or completion of S phase (synthesis of nuclear DNA). In order to test this hypothesis, we have performed a derepression experiment in the presence of 0.075 M hydroxyurea, a level sufficient to inhibit all nuclear DNA synthesis.As can be... 

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