The bacterial artificial chromosome (BAC) RP23-145G23 containing mouse calcium channel, voltagedependent, gamma subunit 5 (Cacng5) gene was modified to insert a Cre-FRT-Amp-FRT cassette at the start site of Cacng5 translation. The ampicillin (Amp) marker was deleted and the Cre-modified BAC's were confirmed, purified and injected into C57BL/6 fertilized pronuclei. Five founders (lines 160, 181, 190, 212, 225) were generated. The 181 Cacng5-Cre line was determined to express Cre selectively in the CA2 area of hippocampus using immunohistochemistry with the anti-Cre antibody, and used for analyses. (J:256034)