12.30-12.45 Valeria Scagliotti
‘Over-expression of Dlk1 in the pituitary gland modulates organ size, stem cell reserve and hormone production’
Abstract: DLK1 is a transmembrane protein that belongs to the Notch/Serrate family and it has been indicated as an important regulator of differentiation. DLK1 is strongly expressed in the murine anterior pituitary gland (AP) during development from embryonic day (E) 10.5 and its expression is maintained during adulthood. Over-expression of Dlk1 from endogenous control elements (Dlk1-TG) has been shown to increase Growth hormone (Gh) mRNA in the AP but the mechanism is yet unclear. Here, we show that over-expression of DLK1 in the AP is associated with an increase in the proliferation rate of the SOX2+ve progenitor cells, prior to cell lineage commitment. As a result, APs from Dlk1-TG mice are hyperplastic, give rise to more stem cell colonies in vitro and contain a higher number of GH+ve cells, when compared with wild-type. Thus, our data indicate that DLK1 affects pituitary development and differentiation by regulating the stem cell reservoir.