L. Cherbas et P. Cherbas, PARAHOMOLOGOUS GENE TARGETING IN DROSOPHILA CELLS - AN EFFICIENT, HOMOLOGY-DEPENDENT PATHWAY OF ILLEGITIMATE RECOMBINATION NEAR A TARGET SITE, Genetics, 145(2), 1997, pp. 349-358
Drosophila cells in culture can be transformed by introducing exogenou
s DNA carrying a selectable marker. Here we report on the fate of plas
mids that contain an extended fragment of Drosophila DNA in addition t
o the selectable marker. A small minority of the resulting transforman
ts appear to arise from homologous recombination at the chromosomal ta
rget. However, the majority of the insertions are the products of ille
gitimate events in the vicinity of the target DNA, and they often caus
e mutations in the targeted region. The efficiency of this process, it
s homology dependence, and the clustering of the products define a nov
el transformation pathway that we call ''parahomologous targeting.''