The effect of exogenous DNA insertion at a chromosomal region containing rDNA

We have previously shown that exogenous DNA may be incorporated into host cell chromosomes following DNA-mediated gene transfer (transformation). Discrete chromosomal changes often accompany the integration event. In this study, the effect of integration of DNA that codes for human growth hormone into a region containing ribosomal DNA in rat chromosomes was investigated. The results show that insertion of exogenous DNA results in the inactivation of the ribosomal DNA and a partial deletion of ribosomal DNA sequences.