A mechanism of palindromic gene amplification in Saccharomyces cerevisiae

摘要: Selective gene amplification is associated with normal development, neoplasia, and drug resistance. One class of events results in large arrays inverted repeats that are often complex structure, thus providing little information about their genesis. We made a recombination substrate Saccharomyces cerevisiae frequently generates palindromic duplications to repair site-specific double-strand break strains deleted for the SAE2 gene. The resulting palindromes stable sae2Delta cells, but unstable wild-type cells. previously proposed formed by invasion break-induced replication, followed an unknown end joining mechanism. Here we demonstrate palindrome formation can occur absence RAD50, YKU70, LIG4, indicating defines new nonhomologous events. Sequence data from 24 independent duplication junctions suggest mechanism utilizes extremely short (4-6 bp), closely spaced (2-9 prime DNA synthesis via intramolecular foldback 3' end. In view our data, present priming model how single copy sequence duplicated generate palindrome.