Strategy for incorporating SIV DNA sequences into the gvpC gene carried in plasmid pFM101d. Plasmid pFM101d contains the rightward gas vesicles operon with the gvp genes (A, C and N). A unique Eco47 III site at location "d", within the gvpC gene, allowed insertion of the exogenous DNA fragments. The unique restriction enzyme sites Spe I, AsiS I and Afl II allowed manipulation/isolation of this cluster of gas vesicle genes by appropriate restriction digests. The antibiotic resistance genes are indicated with the boxes and allow selection of transformed E. coli or SD109 using Ampicilin (Amp) and Mevinolin (mev), respectively.