Insertion element IS1 can generate a 10-base pair target duplication

Abstract Transposable element IS1 is known to generate mainly 9-bp and occasionally 8-bp target duplications upon transposition.We have isolated a plasmid pBR322 derivative having IS1 inserted into a site between the promoter and the structural gene for tetracycline resistance.DNA sequence analysis revealed that integration of this IS1 resulted in a 10-bp target duplication.