A detailed analysis of the molecular events in meiotic recombination of yeast will be carried out. These studies are based on the physical monitoring by Southern blot analysis of DNa from cells undergoing recombination and on the use of in vitro- generated restriction site mutations introduced into a well-defined chromosomal region. (1) A study of the relation between gene conversion and crossing-over in a well-defined 9 kilobase interval will include a measurement of the length of heteroduplex DNA in strains carrying a mutation that reduces mismatch repair. In addition, a secondary mismatch repair-induced recombination system that we have discovered will be investigated. Deletion analysis of the interval will be conducted to determine if there is a single """"""""hotspot"""""""" that initiates the very high level of recombination. Further experiments will also be carried out on a 44 bp region that appears to contain a sequence that acts as a barrier to the extension of (polar) gene conversion events into the region beyond the barrier. (2) Intermediates of meiotic recombination will be identified by physical monitoring techniques. The formation and repair of mismatches in heteroduplex DNA will be examined. A similar approach will be used to investigate the formation and resolution of branched DNa structures (Holliday junctions). (3) We will pursue our study of ectopic recombination between homologous sequences at distant sites. We will extend our studies in Saccharomyces cerevisiae and will carry out similar studies in Schizosaccharomyces pombe. Finally, we will pursue our observation that ectopic recombination between sites on two different chromosomes is sometimes accompanied by chromosomal non- disjunction.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM029736-08
Application #
3277382
Study Section
Genetics Study Section (GEN)
Project Start
1981-09-29
Project End
1994-03-31
Budget Start
1990-04-01
Budget End
1991-03-31
Support Year
8
Fiscal Year
1990
Total Cost
Indirect Cost
Name
Brandeis University
Department
Type
Schools of Arts and Sciences
DUNS #
616845814
City
Waltham
State
MA
Country
United States
Zip Code
02454
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Wilson, J H; Leung, W Y; Bosco, G et al. (1994) The frequency of gene targeting in yeast depends on the number of target copies. Proc Natl Acad Sci U S A 91:177-81
Harris, S; Rudnicki, K S; Haber, J E (1993) Gene conversions and crossing over during homologous and homeologous ectopic recombination in Saccharomyces cerevisiae. Genetics 135:5-16
Haber, J E (1992) Exploring the pathways of homologous recombination. Curr Opin Cell Biol 4:401-12
Haber, J E; Leung, W Y; Borts, R H et al. (1991) The frequency of meiotic recombination in yeast is independent of the number and position of homologous donor sequences: implications for chromosome pairing. Proc Natl Acad Sci U S A 88:1120-4
Lichten, M; Goyon, C; Schultes, N P et al. (1990) Detection of heteroduplex DNA molecules among the products of Saccharomyces cerevisiae meiosis. Proc Natl Acad Sci U S A 87:7653-7
Borts, R H; Leung, W Y; Kramer, W et al. (1990) Mismatch repair-induced meiotic recombination requires the pms1 gene product. Genetics 124:573-84
Borts, R H; Haber, J E (1989) Length and distribution of meiotic gene conversion tracts and crossovers in Saccharomyces cerevisiae. Genetics 123:69-80
Haber, J E; Borts, R H; Connolly, B et al. (1988) Physical monitoring of meiotic and mitotic recombination in yeast. Prog Nucleic Acid Res Mol Biol 35:209-59
Lichten, M; Borts, R H; Haber, J E (1987) Meiotic gene conversion and crossing over between dispersed homologous sequences occurs frequently in Saccharomyces cerevisiae. Genetics 115:233-46

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