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Telomere sequences at the novel joints of four independent amplifications in Saccharomyces cerevisiae
Author(s) -
Moore Irene K.,
Martin Michael P.,
Paquin Charlotte E.
Publication year - 2000
Publication title -
environmental and molecular mutagenesis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1
H-Index - 87
eISSN - 1098-2280
pISSN - 0893-6692
DOI - 10.1002/1098-2280(2000)36:2<105::aid-em4>3.0.co;2-x
Subject(s) - biology , genetics , telomere , chromosome , saccharomyces cerevisiae , breakpoint , gene duplication , gene , genome , microbiology and biotechnology
Primary gene amplification, the mutation from one copy of a gene per genome to two or more genes per genome is a major mechanism of oncogene overexpression. We previously developed a system in the yeast Saccharomyces cerevisiae to phenotypically detect primary amplifications of a reporter cassette, ADH4:CUP1 . We present here the sequence analysis of novel joints from four independent, spontaneous circular amplifications identified by the ADH4:CUP1 system. All four novel joints consist of C 1–3 A telomeric repeats joined to short (14‐ to 16‐bp) CA‐rich tracts between ADH4 and the telomere of chromosome VII. In three of the four amplifications, the telomeric sequence and the CA‐rich tract that are joined in the amplification are normally located in inverted orientation to each other on chromosome VII. In the fourth amplification, the CA‐rich tract on chromosome VII is joined to telomere sequences from another chromosome. We suggest that formation of these amplifications was initiated by recombination between these CA‐rich tracts and a telomere. The resulting dicentric chromosome could start a breakage‐fusion‐bridge cycle that could be resolved by the formation of a circular amplification structure. Environ. Mol. Mutagen. 36:105–112, 2000. © 2000 Wiley‐Liss, Inc.