Temporal and spatial expression of TACC1 in the mouse and human.

TACC1 is the founding member of the evolutionarily conserved transforming acidic coiled coil genes. These genes play a role in normal development and tumorigenesis through interactions with multiple complexes involved in transcription, translation, and centrosomal dynamics. Despite its importance, detailed examination of the expression of TACC1 and splice variants has not previously been performed. In this study, the spatiotemporal distribution of the Tacc1 protein was examined immunohistochemically in cross-sections of mouse embryonic tissues. We also report the distribution of currently known/predicted TACC1 splice variants in adult humans. These results indicate that Tacc1 is regulated in a dynamic manner during embryogenesis. In adult humans, ubiquitous expression of at least one TACC1 splice variant is noted, although specific combinations of variants are evident in individual differentiated tissues. An important observation is that in the in vivo three-dimensional tissue architecture of the growing organism, both the human and mouse TACC1 protein can be localized to different subcellular compartments in a cell- and tissue-specific manner. This indicates that exploration of TACC1 function must take into account the temporal expression of specific splice variants that may perform different cell-type and tissue-specific functions. Furthermore, this analysis will provide the groundwork from which future Tacc1 knockout strategies can be designed and properly interpreted.