In the Saccharomyces cerevisiae mitotic cycle, the timing of radiation-induced gene conversion has been studied using thermosensitive cell division cycle mutants. The cells were found to perform conversion at different G1 or post-replication steps. A lower yield in induction is found during the G2 p
Mitotic gene conversion of large DNA heterologies in Saccharomyces cerevisiae
โ Scribed by Aguilera, Andres
- Publisher
- Springer
- Year
- 1988
- Tongue
- English
- Weight
- 384 KB
- Volume
- 211
- Category
- Article
- ISSN
- 0026-8925
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โฆ Synopsis
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.
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