dmPGE₂ expands short- and long-term hematopoietic activity of the AGM. (A) Colony-forming unit activity was increased by a transient 2-h exposure to dmPGE₂ at 37°C (n = 3 independent experiments; paired Student’s t test: *, P = 0.01; **, P < 0.01). (B) Representative plots show CD45.2⁺ donor contribution to peripheral blood at 10 wk after transplantation. (C) dmPGE₂ potentiated long-term, multilineage engraftment of definitive hematopoietic cells from AGM at E11.5 (2 e.e.) and, to a lesser extent, E10.5 (4 e.e.; n = 5 E10.5 vehicle, n = 5 E10.5 dmPGE₂, n = 4 E11.5 vehicle, n = 8 E11.5 dmPGE₂; two-way ANOVA: *, P < 0.04). (D) Plots show T cell (CD3⁺) and B cell (B220⁺) lymphoid contribution from E10.5 and E11.5 AGM recipients shown in B. (E) Lineages present in CD45.2⁺ donor peripheral blood from individual recipients at 5, 10, 15, and 20 wk after transplantation. Data are represented as mean ± SEM.