FORWARD AND REVERSE GENETIC APPROACHES TO BEHAVIOR IN THE MOUSE

Modern molecular genetic and genomic approaches are revolutionizing th e study of behavior in the mouse. ''Reverse genetics'' (from gene to p henotype) with targeted gene transfer provides a powerful tool to diss ect behavior and has been used successfully to study the effects of nu ll mutations in genes implicated in the regulation of long-term potent iation and spatial learning in mice. In addition, ''forward genetics'' (from phenotype to gene) with high-efficiency mutagenesis in the mous e can uncover unknown genes and has been used to isolate a behavioral mutant of the circadian system. With the recent availability of high-d ensity genetic maps and physical mapping resources, positional cloning of virtually any mutation is now feasible in the mouse. Together, the se approaches permit a molecular analysis of both known and previously unknown genes regulating behavior.