Mex67/TAP/NXF1. A) A C-terminally tagged eYFP fusion protein of the T. brucei putative Mex67 orthologue (Tb11.22.0004) was expressed from its endogenous locus in procyclic trypanosomes. Single plane confocal microscopy images are shown. For comparison, single plane confocal microscopy images of cells expressing an eYFP fusion protein of the nucleoporin NUP54/57 are shown. B) Available genomes of organisms that are representative for five of the six major groups of the eukaryotic kingdom were searched for proteins homologous to the S. cerevisiae Mex67 by Blast. Organisms that have an identifiable Mex67 gene are shown in black/bold, organisms without a readily identifiable Mex67 homologue are shown in grey.