Poorly repaired mismatches in heteroduplex DNA are hyper-recombinagenic in Saccharomyces cerevisiae
- Univ. of Alberta, Edmonton (Canada)
In yeast meiotic recombination, alleles used as genetic markers fall into two classes as regards their fate when incorporated into heteroduplex DNA. Normal alleles are those that form heteroduplexes that are nearly always recognized and corrected by the mismatch repair system operating in meiosis. High PMS (postmeiotic segregation) alleles form heteroduplexes that are inefficiently mismatch repaired. We propose that this hyperrecombination is caused by the high PMS allele blocking a mismatch repair tract initiated from the normal allele, thus preventing corepair of the two alleles, which would prevent formation of recombinants. The results of three point crosses involving two PMS alleles and a normal allele suggest that high PMS alleles placed between two alleles that are normally corepaired block that corepair. 30 refs., 7 figs., 3 tabs.
- OSTI ID:
- 543041
- Journal Information:
- Genetics, Vol. 142, Issue 2; Other Information: PBD: Feb 1996
- Country of Publication:
- United States
- Language:
- English
Similar Records
DNA polymerase I is required for premeiotic DNA replication and sporulation but not for X-ray repair in Saccharomyces cerevisiae
Heteroduplex DNA mismatch repair system of Streptococcus pneumoniae: cloning and expression of the hexA gene