Isolation of early meiotic recombination genes analogous to S. cerevisiae REC104 from the yeasts S. paradoxus and S. pastorianus.

The REC104 gene of Saccharomyces cerevisiae is required to initiate recombination in meiosis. Mutations in REC104 eliminate meiotic recombination and lead to the production of inviable spores. To determine if analogous genes exist in other yeasts, clones that hybridized to a REC104 probe were isolated from the yeasts S. paradoxus and S. pastorianus. When transformed into a rec104 strain, the REC104 analogs from these two yeasts restored spore viability and meiotic recombination to the same level as a REC104 gene cloned from S. cerevisiae. Compared to S. cerevisiae, the S. paradoxus gene codes for 79% identical amino acids and has 86% nucleic-acid identity in the promoter region and 84% in the coding region. The S. pastorianus gene codes for 63% identical amino acids and has 59% and 71% identity in the promoter and the coding regions, respectively.