Genetic dissection of centromere function.
A system to detect a minimal function of Saccharomyces cerevisiae centromeres in vivo has been developed. Centromere DNA mutants have been examined and found to be active in a plasmid copy number control assay in the absence of segregation. The experiments allow the identification of a minimal centromere unit, CDE III, independently of its ability to mediate chromosome segregation. Centromere-mediated plasmid copy number control correlates with the ability of CDE III to assemble a DNA-protein complex. Cells forced to maintain excess copies of CDE III exhibit increased loss of a nonessential artificial chromosome. Thus, segregationally impaired centromeres can have negative effects in trans on chromosome segregation. The use of a plasmid copy number control assay has allowed assembly steps preceding chromosome segregation to be defined.
Schulman
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Department of Biology, University of North Carolina, Chapel Hill 27599-3280.
Bloom
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D002503:Centromere / Q000502:physiology*; D002872:Chromosome Deletion; D015825:Chromosomes, Fungal; D004271:DNA, Fungal / Q000235:genetics* / Q000302:isolation & purification; D005800:Genes, Fungal; D008938:Mitosis / Q000235:genetics; D016296:Mutagenesis; D010957:Plasmids; D015183:Restriction Mapping; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000254:growth & development; D014170:Transformation, Genetic
D004271:DNA, Fungal