title: Mitotic gene conversion of large DNA heterologies in Saccharomyces cerevisiae.
abstract: Gene conversion of large DNA heterologous fragments has been shown to take place efficiently in Saccharomyces cerevisiae. It has been found that a 2.6 kb LEU2 DNA fragment in a multicopy plasmid was replaced by a 3.1 kb PGI1 chromosomal DNA fragment, when both fragments were flanked by homologous DNA regions. Gene conversion was asymmetric in a total of 481 recombinants analyzed. In contrast, truncated PGI1 or LEU2 genes in multicopy plasmids, gave no recombinants that restored a complete plasmid copy of these genes in a total of 242 recombinants studied, confirming that a conversion tract is disrupted by a heterologous region. The asymmetry of the events detected suggest that gene conversion of large DNA heterologies involves a process whereby a gap first covers one heterologous fragment and then this is followed by new DNA synthesis using the other heterologous fragment as a template. Therefore, it is likely that large DNA heterologies are converted by a double-strand gap repair mechanism.
authors.affiliation: Institut für Mikrobiologie, Technische Hochschule Darmstadt, Federal Republic of Germany.
authors.forename: A
authors.initials: A
authors.lastname: Aguilera
mesh_terms: D004271:DNA, Fungal / Q000235:genetics*; D005785:Gene Conversion; D008938:Mitosis; D010957:Plasmids; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000235:genetics*
chemical_list: D004271:DNA, Fungal