Abstract
Thirty years after the first transgenic mouse was produced, a plethora of genetic tools has been developed to study immune cells
in vivo
. A powerful development is the bacterial artificial chromosome (BAC) transgenic approach, combining advantages of both conventional transgenic and knock-in gene-targeting strategies. In immunology the potential of BAC transgenic technology has yet to be fully harvested and, combined with a variety of elegant genetic tools, it will allow the analysis of complex immunological processes
in vivo
. In this short review, we discuss the applications of BACs in immunology, such as identification of regulatory regions, expression and cell-fate mapping, cell ablation, conditional mutations and the generation of humanized mice.