Yeast chromosomes

To clone the restriction fragments, they must each be inserted into a vector. A vector is a piece of DNA (plasmid, viral chromosome, yeast chromosome) capable of autonomous replication in a host cell, for instance, the plasmid pBR322 shown in Figure 1-6-3. The DNA used as a vector usually has... 

Eig. 5. Restriction map of the yeast artificial chromosome (YAC) vector used for cloning very large fragments of eukaryotic DNA. Terms defined in text... 

Muragenicuy, genotoxicity Rats, mice, bacterial strains, yeasts Few days Potential to cause mutations, chromosomal damage, and... 

A Bacterial Artificial Chromosome (BAC) is a vector that allows the propagation of larger exogenous DNA fragments, up to several hundred kb. BACs are propagated in recombination-deficient strains of E. coli. They are more stable and easier to handle than yeast artificial chromosomes (YACs). 

An yeast artificial chromosome (YAC) is a vector that allows the propagation of large exogenous DNA fragments, up to several megabases, in yeast. 

In terms of evolutionary biology, the complex mitotic process of higher animals and plants has evolved through a progression of steps from simple prokaryotic fission sequences. In prokaryotic cells, the two copies of replicated chromosomes become attached to specialized regions of the cell membrane and are separated by the slow intrusion of the membrane between them. In many primitive eukaryotes, the nuclear membrane participates in a similar process and remains intact the spindle microtubules are extranuclear but may indent the nuclear membrane to form parallel channels. In yeasts and diatoms, the nuclear membrane also remains intact, an intranuclear polar spindle forms and attaches at each pole to the nuclear envelope, and a single kinetochore microtubule moves each chromosome to a pole. In the cells of higher animals and plants, the mitotic spindle starts to form outside of the nucleus, the nuclear envelope breaks down, and the spindle microtubules are captured by chromosomes (Kubai, 1975 Heath, 1980 Alberts et al., 1989). 

This indicates that endosulfan is capable of inducing chromosome breakage and loss. Endosulfan also induced cytotoxic activity (significant increase in the number of crossover colonies) in the yeast strain S. cerevisiae T2 (deficient in repair system), but not in S. cerevisiae T1 (L Vova 1984). 

Abbreviations STS, sequence tagged site RFLP, restriction fragment iinked poiymorphism SNP, singie nucieotide poiymorphism YAC, yeast artificiai chromosome BAC, bacteriai artificiai chromosome PCR, poiymerase chain reaction. 

Blat Y, Kleckner N 1999 Cohesins bind to preferential sites along yeast chromosome III, with differential regulation along arms versus the centric region. Cell 98 249-259... 

Saka Y, Sutani T, Yamashita Y et al 1994 Fission yeast cut3 and cutl4, members of a ubiquitous protein family, are required for chromosome condensation and segregation in mitosis. EMBO J 13 4938-4952... 

Nasmyth In the yeast, most of the cleavage takes place in a Polo mutant, and the centromeres go to the poles quite normally. But the chromosomes don t fully disengage. We suspect about 10% of the Sccl may not be coming off. If you make a Pdsl /Polo double mutant (which is difficult because they are almost synthetic lethal), then it looks like there isn t much anaphase at all. But these are recent, preliminary results. 

Lehner There is a paper by Goldstein (1981) in which he describes electron microscope (EM) studies of meiotic chromosomes. At meiosis I, chromosomes do not have two sister kinetochores. There is a maturation into two kinetochores between the two meiotic divisions. Have comparable EM analyses been done in yeast ... 

Nasmyth Cytologically we don t see it associated with chromosomes. From an indirect assay, if we isolate yeast chromosomes there is Espl there. We have a biological assay for that. 

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