Bac to the future: The use of bac transgenic mice for neuroscience research

The development of methods for engineering bacterial artificial chromosomes (BACs), and for the efficient production of BAC transgenic mice, has allow ed the design of in vivo approaches to the analysis of gene expression and function in the brain, which could not be accomplished using traditional me thods. These strategies have shed light on the functions of single genes in the nervous I system, and will accelerate the use of functional genomic ap proaches to neuroscience research.