Analysis of spontaneous deletions and gene amplification in the lac region of Escherichia coli

Spontaneous rearrangements, such as large deletions and duplications, have important implications for the structure of the genome. It is therefore of great interest to analyze these events at the molecular level. We have constructed derivatives of a lacI-Z fusion strain, which allow us to study deletions in a more systematic manner than was previously possible. These derivatives have been used to investigate how frequently larger deletions (> 700 bp) occur between short homologies on both recA and recA- strains and to determine the effect of the lengths of the short homologies and of the distance between homologies on the frequency of deletion formation. 38 references, 11 figures