Iterons of stringently controlled plasmids and DNA fingerprinting

DNA probes which detect polymorphic, repetitive sequences in a variety of genomes have been developed using different approaches. Naturally occurring plasmids, with repeated units termed iterons near or within their origins (ori) or replication, could be of interest for the development of probes, possibly even revealing novel minisatellite families in mammals involved in replicational processes. We used the plasmids P1, pSC101 and RSF1010 or their PCR amplified ori regions as probes in Southern blot hybridisations with mammalian DNA. At low stringency they generated reproducible fingerprint-like patterns. A bovine genomic library was screened at the same stringency with the PCR-amplified ori region of P1 containing the five times repeated core sequence 5'-ATGTGTGNTGNNGGG-3' to generate a probe for cattle DNA with higher specificity.