Gpr101 expression during early stages of murine development.

The orphan G protein coupled receptor GPR101, which is implicated in X-linked acrogigantism (X-LAG), a rare pituitary disorder characterized by rapid growth a few years after birth, has received significant attention for its expression pattern in adult vertebrate tissues. However, the characterization of GPR101 expression during early embryonic development is poorly characterized. In this study, we investigated the spatiotemporal expression patterns of Gpr101 during early embryonic mouse development (E7.5-E15.5) using a global Gpr101 knock-in mouse model with an inserted LacZ reporter, Gpr101tm1b(KOMP)Mbp. Similar to previously published studies using adult tissues, we found that LacZ reporter expression was largely restricted to regions of the central nervous system. Expression was not detected until E10.5 in a region near the telencephalic vesicle. In contrast to what has been reported in adult tissues, Gpr101 expression was absent in the hypothalamus and pituitary gland during the developmental timepoints assessed. These novel observations provide a more comprehensive characterization of GPR101's expression and may offer insights into its role in growth and development across species.