Cis-acting determinants affecting centromere function, sister-chromatid cohesion and reciprocal recombination during meiosis in Saccharomyces cerevisiae

Journal Article · Wed Mar 01 04:00:00 EST 1995 · Genetics

OSTI ID:75589

Sears, D D; Hieter, P ^[1]; Shero, J H ^[1]; Hegemann, J H ^[2]

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1. Johns Hopkins Univ. School of Medicine, Baltimore, MD (United States)
2. Justus Liebig Universitaet, Giessen (Germany)

We have employed a system that utilizes homologous pairs of human DNA-derived yeast artificial chromosomes (YACs) as marker chromosomes to assess the specific role(s) of conserved centromere DNA elements (CDEI, CDEII, and CDEIII) in meiotic chromosome disjunction fidelity. Thirteen different centromere (CEN) mutations were tested for their effects on meiotic centromere function. YACs containing a wild-type CEN DNA sequence segregate with high fidelity in meiosis I (99% normal segregation) and in meiosis II (96% normal segregation). YACs containing a 31-bp deletion mutation in centromere DNA element II (CDEII{Delta}31) in either a heterocentric (mutant/wild type), homocentric (mutant/mutant) or monosomic (mutant/-) YAC pair configuration exhibited high levels (16-28%) of precocious sister-chromatid segregation (PSS) and increased levels (1-6%) of nondisjunction meiosis I (NDI). YACs containing this mutation also exhibit high levels (21%) of meiosis II nondisjunction. Interestingly, significant alterations in homolog recombination frequency were observed in the exceptional PSS class of tetrads, suggesting unusual interactions between prematurely separated sister chromatids and their homologous nonsister chromatids. We also have assessed the meiotic segregation effects of rare gene conversion events occurring at sites located immediately adjacent to or distantly from the centromere region. Proximal gene conversion events were associated with extremely high levels (60%) of meiosis I segregation errors (including both PSS and NDI), whereas distal events had no apparent effect. Taken together, our results indicate a critical role for CDEII in meiosis and underscore the importance of maintaining sister-chromatid cohesion for proper recombination in meiotic prophase and for proper disjunction in meiosis I. 49 refs., 4 figs., 5 tabs.

• OSTI ID: 75589
• Journal Information: Genetics, Journal Name: Genetics Journal Issue: 3 Vol. 139; ISSN GENTAE; ISSN 0016-6731
• Country of Publication: United States
• Language: English

Related Subjects

55 BIOLOGY AND MEDICINE
BASIC STUDIES
BIOLOGICAL MARKERS
CENTROMERES
CHROMATIDS
CHROMOSOMAL ABERRATIONS
CHROMOSOMES
DNA
DNA SEQUENCING
GENE RECOMBINATION
MEIOSIS
NON-DISJUNCTION
SACCHAROMYCES CEREVISIAE
STRUCTURE-ACTIVITY RELATIONSHIPS