Fitness effects of horizontal gene transfer

In their natural habitats, bacteria live in close contact with other species. Genomic studies reveal plentiful evidence of gene transfer across different species. However, little is known about its rates and fitness effects. What are limiting factors of cross-species gene transfer? Can the entire genome be exchanged between two species? How does gene transfer affect bacterial fitness? While gene transfer can benefit bacteria during adaptation to new niches, it also bears the potential of reducing fitness by introducing maladapted genes. We study these trade-offs by combining experimental evolution with genomics, transcriptomics, and molecular biology.