%0 Journal Article %J Genetics %D 1990 %T Synapsis-mediated
fusion of free DNA ends forms inverted dimer plasmids in yeast.
%A Kunes, S %A Botstein, D %A Fox, M S %X  When yeast
(Saccharomyces cerevisiae) is transformed with linearized
plasmid DNA and the ends of the plasmid do not share homology
with the yeast genome, circular inverted (head-to-head) dimer
plasmids are the principal product of repair. By measurements of
the DNA concentration dependence of transformation with a
linearized plasmid, and by transformation with mixtures of
genetically marked plasmids, we show that two plasmid molecules
are required to form an inverted dimer plasmid. Several
observations suggest that homologous pairing accounts for the
head-to-head joining of the two plasmid molecules. First, an
enhanced frequency of homologous recombination is detected when
genetically marked plasmids undergo end-to-end fusion. Second,
when a plasmid is linearized within an inverted repeat, such
that its ends could undergo head-to-tail homologous