MKK3 and pMKK3 mainly localized to the antennules of barnacle cyprids.

<p>Cyprids were stained with MKK3 and pMKK3 antibodies. Larvae stained with secondary antibody alone were used as control. Images were obtained using a laser scanning confocal microscope with a 20X objective. Both MKK3 and pMKK3 were mainly concentrated at the third segment and the attachment organ of antennules.