Fig. 2

MVP expression is highly specific to the limbic system. A, B Mvp qRT-PCR expression in the liver (LIV), cerebellum (CRB), hippocampus (HP), and cortex (CTX), in male (A) and female (B) WT mice. Normalization was done using the Gnas/Hprt ratio. Plots are shown as mean ± SEM. Immunofluorescence of MVP (green) in CRB (C), ventral HP (D), and deep layers of the cingulate gyrus (Cg) (E). Arrowheads point to MVP-positive cells. AV, arbor vitae; gr/mole, granular/molecular layer of CRB; or/py, oriens/pyramidal layer of HP. F–O Selection of MVP immuno-histo-fluorescence (IHF) images on the coronal brain sections, each of 30 µm in thickness, performed throughout the entire brain from bregma + 1.41 mm to bregma − 7.67 mm. MVP presence was revealed using an anti-vault antibody (N2-B15) and secondary antibodies fused to Alexa488 fluorochrome (green). Dashed lines delineate regions with MVP-positive cells (white), MVP-positive tract (yellow), and MVP-negative cells (gray). It is noteworthy to mention that the experiment was repeated on a new set of brain samples on sagittal orientation, ranging from lateral + 0.24 mm to lateral + 0.84mm. Quantitative analysis both on the coronal and sagittal sections was done, and MVP expression was scored as mild (+), moderate (++), or strong (+++) across all the positive brain regions. The complete analysis is available in Additional file 2: Tables S3-S4. Pir, piriform cortex; MS, medial septum; DBB, diagonal band of Broca; TS, triangular septal nucleus; ZI, zona incerta; RM, retromammillary nucleus; py/mol, pyramidal/molecular layer of the hippocampus (HP); DG, dentate gyrus of the hippocampus; 4V, fourth ventricle; CP, choroid plexus; MVe, medial vestibular nucleus; Sol, solitary nucleus; AP, area postrema; 10N, vagus nucleus; Raphe, raphe magnus nucleus. P, Q IHF of MVP, NeuN neurons, and Hoechst on the brain sections from male (P) and female (Q) WT mice. The dashed square delineates the region presented at a higher magnification on individual channels for MVP, NeuN, and Hoechst, and merge of the three. In all structures, the MVP signal came from the cytoplasm