title: Construction and behavior of circularly permuted and telocentric chromosomes in Saccharomyces cerevisiae.
abstract: We developed techniques that allow us to construct novel variants of Saccharomyces cerevisiae chromosomes. These modified chromosomes have precisely determined structures. A metacentric derivative of chromosome III which lacks the telomere-associated X and Y' elements, which are found at the telomeres of most yeast chromosomes, behaves normally in both mitosis and meiosis. We made a circularly permuted telocentric version of yeast chromosome III whose closest telomere was 33 kilobases from the centromere. This telocentric chromosome was lost at a frequency of 1.6 X 10(-5) per cell compared with a frequency of 4.0 X 10(-6) for the natural metacentric version of chromosome III. An extremely telocentric chromosome whose closet telomere was only 3.5 kilobases from the centromere was lost at a frequency of 6.0 X 10(-5). The mitotic stability of telocentric chromosomes shows that the very high frequency of nondisjunction observed for short linear artificial chromosomes is not due to inadequate centromere-telomere separation.
mesh_terms: D002875:Chromosomes / Q000502:physiology*; D003433:Crosses, Genetic; D014644:Genetic Variation; D005838:Genotype; D008938:Mitosis; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000235:genetics*