Embryonic expression of pericentrin suggests universal roles in ciliogenesis.

Pericentrin (Pcnt) is a giant coiled-coil protein known to mediate microtubule organization. It has been recently reported that mitosis-specific centrosomal anchoring of gamma tubulin complexes by Pcnt acts to control mitotic spindle organization, though little is known about the in vivo expression of Pcnt. In this study, we investigated Pcnt expression in mouse embryos. In situ hybridization analysis revealed preferential expression of Pcnt in quiescent G(0) phase cells throughout the embryo with an unexpectedly low expression level in proliferating cells, suggesting that Pcnt might not play an important role in mitotic proliferation. Immunofluorescence analysis confirmed preferential expression of the Pcnt protein in G(0) phase cells. Moreover, Pcnt was shown to be localized to the base of primary cilia in multiple embryonic tissues, in agreement with a recent study demonstrating the involvement of Pcnt in primary cilia formation using cultured mammalian cells.