Nature and distribution of chromosomal intertwinings in Saccharomyces cerevisiae
- Harvard Univ., Cambridge, MA (United States)
To elucidate yeast chromosome structure and behavior, we examined the breakage of entangled chromosomes in DNA topoisomerase 11 mutants by hybridization to chromosomal DNA resolved by pulsed-field gel electrophoresis. Our study reveals that large and small chromosomes differ in the nature and distribution of their intertwinings. Probes to large chromosomes (450 kb or larger) detect chromosome breakage, but probes to small chromosomes (380 kb or smaller) reveal no breakage products. Examination of chromosomes with one small arm and one large arm suggests that the two arms behave independently. The acrocentric chromosome XIV breaks only on the long arm, and its preferred region of breakage is approximately 200 kb from the centromere. When the centromere of chromosome XIV is relocated, the preferred region of breakage shifts accordingly. These results suggest that large chromosomes break because they have long arms and small chromosomes do not break because they have small arms. Indeed, a small metacentric chromosome can be made to break if it is rearranged to form a telocentric chromosome with one long arm or a ring with an {open_quotes}infinitely{close_quotes} long arm. These results suggest a model of chromosomal intertwining in which the length of the chromosome arm prevents intertwinings from passively resolving off the end of the arm during chromosome segregation. 61 refs., 7 figs., 3 tabs.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 577153
- Journal Information:
- Molecular and Cellular Biology, Journal Name: Molecular and Cellular Biology Journal Issue: 2 Vol. 14; ISSN 0270-7306; ISSN MCEBD4
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
BASIC STUDIES
56 BIOLOGY AND MEDICINE
APPLIED STUDIES
ACROCENTRIC CHROMOSOMES
CENTROMERES
CHROMOSOMAL ABERRATIONS
CHROMOSOME BREAKAGE
CHROMOSOMES
DNA
DNA HYBRIDIZATION
DNA REPLICATION
ELECTROPHORESIS
FUNCTIONAL MODELS
GAMMA RADIATION
ISOMERASES
LENGTH
MITOSIS
MUTANTS
SACCHAROMYCES CEREVISIAE
SENSITIVITY
SISTER CHROMATID EXCHANGES
SIZE
STRUCTURE-ACTIVITY RELATIONSHIPS