ISSN:
1617-4623
Keywords:
Key words Trinucleotide repeats
;
Double-strand break repair
;
Gene conversion
;
Yeast
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Trinucleotide repeats undergo contractions and expansions in humans, leading in some cases to fatal neurological disorders. The mechanism responsible for these large size variations is unknown, but replication-slippage events are often suggested as a possible source of instability. We constructed a genetic screen that allowed us to detect spontaneous expansions/contractions of a short trinucleotide repeat in yeast. We show that deletion of RAD27, a gene involved in the processing of Okazaki fragments, increases the frequency of contractions tenfold. Repair of a chromosomal double-strand break (DSB) using a trinucleotide repeat-containing template induces rearrangements of the repeat with a frequency 60 times higher than the natural rate of instability of the same repeat. Our data suggest that both gene conversion and single-strand annealing are major sources of trinucleotide repeat rearrangements.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s004380050031
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