A proposal for using modified site-specific recombination systems for making insertions into a chosen chromosomal site in vivo based on the analysis of lambda phage integration.

A proposal is presented here to use modified mobile genetic elements for making chromosomal insertions in vivo, into any desired chromosomal site. The idea lies in replacing the sequences which direct specificity of integration of those elements with other DNA sequences, homologous to the desired target chromosomal site. The idea is analysed on the basis of a lambda phage integration system. A design for a universal system for making chromosomal insertions into any site of choice is proposed.