Serotonin neurons modulate most homeostatic Central Nervous System (CNS) functions while influencing the expression of behavioral traits such as mood, aggression and anxiety. Serotonin neuron dysfunction has been implicated in depression, addiction, autism and sudden infant death syndrome. This disclosure describes a straightforward, highly reproducible method for genetically accessing serotonin neurons and a sub-population of intestinal enterocytes, in vivo, using BAC-based transgenes that can be constructed using simple subcloning procedures. Compositions described herein include these transgenes and methods for making and using them to create transgenic mouse strains and identify serotonin and intestinal enterocytes without immunostaining.
