Break-induced replication and telomerase-independent telomere maintenance require Pol32

摘要: Break-induced replication (BIR) is an efficient homologous recombination process to initiate DNA when only one end of a chromosome double-strand break shares homology with template. BIR thought re-establish at stalled and broken forks act eroding telomeres in cells that lack telomerase pathways known as 'alternative lengthening telomeres' (reviewed refs 2, 6). Here we show that, haploid budding yeast, Rad51-dependent induced by HO endonuclease requires the lagging strand Polalpha-primase complex well Poldelta new synthesis. Polepsilon not required for initial primer extension step but complete 30 kb Initiation also nonessential subunit Pol32 primarily through its interaction another subunit, Pol31. HO-induced gene conversion, which both ends engage recombination, does require Pol32. recovery Rad51-independent survivors yeast strains lacking telomerase. These results strongly suggest types telomere maintenance occur recombination-dependent replication. Thus Pol32, dispensable uniquely BIR; this finding provides opening into understanding how re-start mechanisms operate eukaryotes. We note homologues have been identified fission metazoans where telomerase-independent alternative identified.