Localization of SOX2-positive stem/progenitor cells in the anterior lobe of the common marmoset (Callithrix jacchus) pituitary.

Studies on mouse and rat pituitaries reported that Sox2-expressing cells play roles as stem/progenitor cells in the adult pituitary gland. The presence of cells with stem cell-like properties in the pituitary adenoma and SOX2-positive cells has been demonstrated in the human pituitary. However, considering the difficulty in fully examining the stem/progenitor cell properties in the human pituitary, in the present study, we analyzed the SOX2-positive cells in the pituitary of the adult common marmoset (Callithrix jacchus), which is used as a non-human primate model. Immunohistochemistry demonstrated that localization pattern of SOX2-positive cells in the common marmoset pituitary was similar to that observed in the rodent pituitary, i.e., in the two types of niches (marginal cell layer and parenchymal-niche) and as scattered single cells in the parenchyma of the anterior lobe. Furthermore, most of the SOX2-positive cells express S100 and were located in the center or interior of LAMININ-positive micro-lobular structures. Collectively, the present study reveals properties of SOX2-positive cells in the common marmoset pituitary and suggests that the common marmoset proves to be a useful tool for analyzing pituitary stem/progenitor cells in a non-human primate model.