Two new tools: multi-purpose cloning vectors that carry kanamycin or spectinomycin/streptomycin resistance markers.

We have constructed two new multi-purpose cloning vectors, pJKKmf(-) and pJKSp/Smf(-), that carry resistance to kanamycin (Km) and spectinomycin/streptomycin (Sp/Sm), respectively. These plasmids are based on pGEM3Zf(-) and therefore contain a pUC-vector-derived multiple cloning site for 13 restriction sites flanked by T7 and SP6 RNA polymerase promoters, the alpha-peptide coding region of beta-galactosidase for blue/white colony screening and the bacteriophage f1 origin of replication for production of single-stranded DNA in the presence of a helper phage. We have used these vectors to reclone sequences from a maize genomic library, to produce radiolabeled RNA probes and to make single-stranded DNA.