Fig. 1

Irf4 Is Expressed in Lymphoid Progenitors at Embryonic Stages

(A) Expression pattern of irf4a examined by WISH. The expression of irf4a was observed in the CHT at 2 dpf and later in the thymus at 3 dpf. Red arrows indicate irf4a-expressing cells. The magnified view of the boxed region is shown in the right panel, and the thymus is denoted with red circle.

(B) Absence of irf4a expression in the CHT of the cloche mutants and runx1 morphants.

(C) qPCR of irf4a in sorted cells from 3-dpf transgenic embryos. Irf4a is highly expressed in cmyb:EGFP⁺ cells relative to negative cells but is not expressed in mpo:EGFP cells or gata1:GFP cells. The purity of mpo:EGFP cells or gata1:GFP cells was validated by the high expression level of lyz or gata1, respectively, with β-actin as the control. p < 0.001. nd, not detectable.

(D) Expression of irf4a in a subset of cmyb-expressing cells in the CHT revealed by double color FISH. The cell denoted by the white arrow is shown in the insets with a magnified view. Scale bar, 20 µm.

(E) Western blot showed the protein level of IRF4 in the FL (E11.5, E12.5, and E14.5) or thymus (E16.5) of mouse embryos.

(F) Expression of IRF4 in the FL of E14.5 mouse embryos examined by immunochemistry. Red arrows indicate IRF4-expressing cells. Scale bar, 200 µm.

(G) qPCR analysis of the relative mRNA level of Irf4 in purified hematopoietic cells from the FL of E13.5 mouse embryos.

(H) Expression of IRF4 was observed in CCR9⁺ cells sorted and photographed using FlowSight (Merck-Millipore). Scale bar, 20 µm. All data are mean ± SD.

See also Figure S1 and Table S1.