We have combined our expertise in purifying mRNA localization complexes with whole genome microarrays to systematically profile the mRNAs that are present in a given localization complex. We have already applied this approach to the Trailer Hitch complex and we have identified a number of mRNA targets involved in ER to Golgi transport - consistent with our finding that Trailer Hitch is required for efficient secretion. We are now expanding our whole genome screens to other subunits in order to identify the targets associated with other uncharacterized localization complexes.