Research Product

Three major systems of genetic transfer are recognized in bacteria: conjugation, transduction, and transformation. These systems have been used routinely in the laboratory as tools of genetic analysis for many years, but their importance in investigating microbial genetic diversity and evolution in natural habitats has only recently begun to be investigated. To date, most environmental studies have focused on the potential for conjugation to transfer extra-chromosomal elements among microbes of the same or different species. Transduction (virus-mediated, horizontal gene transfer) has often been discounted as a potentially important process for the redistribution of genetic information (both chromosomal and extra-chromosomal) in bacterial populations because it is reductive (i.e., the donor is killed in the process of donating its genetic material to the recipient). However, recent reports have documented that transduction can be a fertile gene exchange system in natural ecosystems. We are using Pseudomonas aeruginosa as a model organism to study virus-mediated gene transfer in freshwater microbial populations. Our studies have revealed a significant potential for transduction of both plasmid and chromosomal DNA in these environments.