A sequence cassette has been introduced into the attP site present in TI{TI}CCHa2-R^attP, restoring the deleted CCHa2-R sequence and tagging isoform A with Tag:V5. The tag is followed by a 2A-lexA::GAD cassette, resulting in the lexA::GAD driver being expressed as a separate protein under the control of the endogenous CCHa2-R regulatory sequences (only the expression of isoform A is trapped by lexA::GAD). A single loxP site is present downstream of the driver sequence (markers present in the progenitor insertion and donor plasmid have been removed using P1cre).