Expression patterns of imprinted gene Inpp5f-v3 during mouse brain development.

Inpp5f-v3 is a transcriptional variant of Inpp5f (inositol polyphosphate-5-phosphatase F) and locates in distal mouse chromosome 7. It is a paternally expressed imprinted gene in mouse. In this study, we examined the spatiotemporal patterns of Inpp5f-v3 gene during the mouse development. The northern blotting analysis revealed that only one transcript approx 2.7 kb of Inpp5f-v3 was detected in brain. The signals were only observed in brain by the whole-mount in situ hybridization at embryonic day 11.5 (E11.5). The results of quantitative real-time PCR (QRT-PCR) showed that the expression of Inpp5f-v3 increased gradually from the E11.5 to E17.5 and reached the highest at E17.5, then decreased at E18.5 during the brain development. Inpp5f-v3 gene was strongly expressed in the cerebral cortex, olfactory bulb, external germinal layer of cerebellum and ventricular zone (Vz) during the embryonic development (E15.5-E19.5), whereas the expression increased in the olfactory bulb and the cerebellum after birth by using in situ hybridization. The results also demonstrated that the expression of Inpp5f-v3 gene mainly located in olfactory bulb and hippocampus at postnatal day 7 (P7) and adulthood. These results suggest that Inpp5f-v3 is specifically expressed in mouse brain, and may function in the development of mouse brain.