volume 9 Number 121981 Nucleic Ac ids Research Cloning of multiple copies of immunoglobulin variable kappa genes in cosmid vectors

The possibility of cloning large segments of DNA in cosmid vectors offers distinct advantages, in particular for the study of multigene families. Large size fragments of mouse embryo DNA were successfully cloned in the cosmid pHC 79. Twelve recombi-nants hybridizing specifically to an immunoglobulin kappa chain variable region probe were identified. In 9 of these recombi-nants, the size of the insert ranges from 31 to 43 kilobases. Factors affecting the cloning efficiency of a complex mammalian genome in cosmids were studied. The stability of these recombi-nant cosmids and the preparation of recombinant cosmid DNA are also discussed