The focus of this research is to study gene transfer among marine microbial communities through the application of molecular techniques that avoid the selective process of isolation and cultivation. Since genetic material can be transferred to receptive hosts without gene expression, this study will be designed to detect the presence of marker gene sequences transferred by phage transduction to recipient microbial hosts and complemented with studies designed to determine the frequency of subsequent gene expression of the marker sequences in recipient hosts. Biotintylated probes have been developed for visualizing the presence of viral sequences in virus-infected cells and, because of its sensitivity and specificity, is the most appropriate approach for tracking specific gene sequences in native microbial communities. This methodology will be applied to the study of plasmid DNA transduction by a generalized transducing vibriophage. The ecologically important role of particulate organic matter on the growth rate of the donor host, vibriophages, gene recipient hosts, phage/host encounter rates, bacteriophage survival and gene transduction frequency will be investigated. The results of these studies on gene transduction in vibriophages isolated from the marine environment will serve as a model for gene transfer in marine microorganisms and indicate the potential importance of gene transfer in native marine microbial communities.
