Fig. 2

Zip1 is primarily localized to the luminal membrane in lactating mouse mammary gland. Mouse mammary gland was fixed, embedded in paraffin and sectioned (4 μm). Localization of Zip1 was detected using affinity purified Zip1 antibody and counterstained with toluene blue; X60. Zip1 was not detected in the mammary gland of Zip1 knock-out mice (a) but was clearly visible associated with the luminal membrane in wild-type mice (b arrow)