Results . Men1 is expressed in the peri-implantation mouse uterus in a spatiotemporal manner . Highly heterogeneous uterine endometrium is comprised of different cell types that undergo tremendous changes during early pregnancy. To elucidate the physiological significance of Men1 during early pregnancy, we first examined the cell-specific and temporal expression of Men1 in peri-implantation uteri using in situ hybridization. There was weak Men1 expression in the pre-implantation ute...