Localization of mRNAs for phosphatidylinositol phosphate kinases in the mouse brain during development

Abstract

The gene expression for seven phosphatidylinositol phosphate kinases (PIPKs)—types Iα, Iβ, Iγ, types IIα, IIβ, IIγ, and type III—was examined using in situ hybridization histochemistry, in the mouse brain during normal development. In the embryonic mouse brain, positive expression signals were detected only for the genes encoding PIPK Iγ and PIPK IIβ in both the cerebral ventricular and mantle zones, with weaker signals in the former zone. On the other hand, the genes encoding all PIPKs were essentially detected in the external granule cell layer which represents the germinal zone for the neuronal granule cells. In the postnatal brain, among the seven PIPKs, the expression for genes encoding PIPK Iγ and IIβ is evident in most gray matter, while the expression for the other five types was weak in the cortical gray matter and negligible in most non-cortical gray matter such as the diencephalon and brain stem nuclei. While the expression for most PIPKs in the mature hippocampus was distinct, the expression in the CA3 and the dentate gyrus was less definite for the genes encoding PIPK Iα and IIγ, respectively. The distinct expression for the gene encoding PIPK IIα was detected in the postnatal white matter such as the cerebellar medulla, the corpus callosum, the hippocampal fimbriae, and the internal capsule.