Meiotic chromosome segregation in triploid strains of Saccharomyces cerevisiae.
Meiosis in triploids results in four highly aneuploid gametes because six copies of each homolog must be segregated into four meiotic products. Using DNA microarrays and other physical approaches, we examined meiotic chromosome segregation in triploid strains of Saccharomyces cerevisiae. In most tetrads with four viable spores, two of the spores had two copies of a given homolog and two spores had only one copy. Chromosomes segregated randomly into viable spores without preferences for generating near haploid or near diploid spores. Using single-nucleotide polymorphisms, we showed that, in most tetrads, all three pairs of homologs recombined. Strains derived from some of the aneuploid spore colonies had very high frequencies of mitotic chromosome loss, resulting in genetically diverse populations of cells.
St Charles
Jordan
J
Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA.
Hamilton
Monica L
ML
Petes
Thomas D
TD
D000782:Aneuploidy; D043171:Chromosomal Instability; D002874:Chromosome Mapping; D023902:Chromosome Pairing; D020090:Chromosome Segregation; D015825:Chromosomes, Fungal / Q000235:genetics; D008540:Meiosis; D020411:Oligonucleotide Array Sequence Analysis; D016133:Polymerase Chain Reaction; D020641:Polymorphism, Single Nucleotide; D011995:Recombination, Genetic; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000502:physiology; D013172:Spores, Fungal / Q000235:genetics; D057885:Triploidy