unequal crossing-over In genetics, a cross-over after improper pairing between chromosome homologues that are not perfectly aligned. The result is 1 cross-over chromatid with 1 copy of the segment and another with 3 copies. The phenomenon was first described at the Bar locus in Drosophila (fruit fly).

unequal crossing over The crossing over of genetic information between two homologous chromosomes at different chromosomal positions, resulting in a disproportional exchange. In regions of repetitive DNA this results in changes in the copy number of repeats on both chromosomes and successive events will ultimately result in the fixation of one type of repeat.

unequal crossing-over In genetics, a crossing-over after improper pairing between homologous chromosomes that are not perfectly aligned. The result is one cross-over chromatid with one copy of the segment and another with three copies. The phenomenon was first described at the Bar locus in Drosophila.