Generation of BAC Transgenic Mice

Transgenic mice provide an important experimental system for studying the effects of gene overexpression and for analyzing the expression of well-characterized “single” genes that contribute to a particular trait. However, single-gene expression in transgenic (Tg ) mice is not appropriate for the functional analysis of the many genes that may reside in a typical genetically mapped locus of the order of 1 cM. Bacterial artificial chromosome (BAC) vectors, which can accommodate large genomic intervals of up to 300 kb are appropriate for such studies (1 ). BACs of this size may contain several contiguous genes along with their cis -acting regulatory elements. As such, BACs are valuable tools in complementation or “rescue” experiments for identifying genes contributing to a genetically mapped quantitative trait of interest.