C. Campbell et al., UNEQUAL HOMOLOGOUS RECOMBINATION OF HUMAN DNA ON A YEAST ARTIFICIAL CHROMOSOME, Nucleic acids research, 23(18), 1995, pp. 3691-3695
We examined unequal homologous DNA recombination between human repetit
ive DNA elements located on a yeast artificial chromosome (YAC) and tr
ansforming plasmid molecules, A plasmid vector containing an Alu eleme
nt, as well as a sequence identical to a unique site on a YAC, was int
roduced into yeast and double recombinant clones analyzed, Recombinati
on occurs between vector and YAC Alu elements sharing as little as 74%
identity, The physical proximity of an Alu element to the unique DNA
segment appears to play a significant role in determining the frequenc
y with which that element serves as a recombination substrate, In addi
tion, cross-over points of the recombination reaction are largely conf
ined to the ends of the repetitive element, Since a similar distributi
on of crossover sites occurs during unequal homologous recombination i
n human germ and somatic tissue, we propose that similar enzymatic pro
cesses may be responsible for the events observed in our system and in
human cells, This suggests that further examination of the enzymology
of unequal homologous recombination of human DNA within yeast may yie
ld a greater understanding of the molecular events which control this
process in higher eukaryotes.