Figure 3

Expression of the pW224 transgene visualized by β-galactosidase activity to confirm that the resulting transgene is able to faithfully recapitulate the expression of endogenous Umodl1. Panels in the first and third columns show the lacZ positive whole mount organs; while the expression of the transgene is detailed in sections shown in panels listed in the second and fourth columns. Developmental stages of the specimens are indicated on top of the columns. Umodl1-Tg is one of the earliest developmental genes expressed in vomeronasal organ(a and b), thymus (a, e and f), inner ear (c and d), and embryonic ovary (g and h). In the young adult mice, Umodl1-Tg expression in olfactory neurons, vomeronasal organs is maintained (i and j). Meanwhile, axonal cells in the glomerular layer of olfactory bulbs show a high level of Umodl1-Tg (k and l). In thymus, its expression is restricted to the antigen-presenting cells (m and n). In the young female reproductive system, Umodl-Tg is solely expressed in the maturing oocytes (o and p), which is consistent with the ISH data on the endogenous Umodl1. Arrows and arrowheads in o indicate expanded antral follicles and densely packed preantral follicles, respectively. Scale bars, 100 μm