Histological characterization of brains of Nsrp70 knockout and Vstm5 knockout mice

Abstract

Nuclear speckle-related protein 70 (Nsrp70), a novel nuclear speckle protein molecule, is an alternative splicing regulator essential in early embryonic development. The membrane glycoprotein V-set and transmembrane domain-containing protein 5 (Vstm5) is a cell adhesion molecule that plays critical roles in synaptogenesis and corticogenesis in the vertebrate nervous system by controlling neuronal membrane dynamics. Nsrp70 and Vstm5 are expressed in the mouse brain, but the functions of these molecules are unknown in them. Therefore, I focused on the function of Nsrp70 and Vstm5 both in embryonic and adult mouse brains. First, I compared the layer thickness of the cortex and analyzed the morphology of the major brain areas such as cortex, hippocampus, and thalamus using nissl staining to identify the status of neurons. There was no discernible difference in the brains of Nsrp70 cKO and Vstm5 KO mice compared to control littermates. Next, I investigated myelin structures that are important for the normal function of the nervous system using luxol fast blue staining. As a result, there was no difference in the thickness and myelination of the corpus callosum in Nsrp70 cKO and Vstm5 KO mice. Furthermore, there was no difference in Nsrp70 cKO and Vstm5 KO mice in major axonal tracts of the embryonic mouse brain including corticothalamic axons, thalamocortical axons and subcerebral axons. These results suggest that Nsrp70 and Vstm5 deficiency do not cause major structural abnormalities in the brain.