Figure 1.

JMJD1A and JMJD1B Are Essential for Mouse Embryogenesis

(A) Immunofluorescence analysis of longitudinal sections of the E6.5 embryos with JMJD1A (left) and JMJD1B (right). E6.5 wild-type embryos were stained with anti-JMJD1A antibodies and DAPI (left). E6.5 Jmjd1b^+/Flag−KI embryos were stained with anti-FLAG antibodies and DAPI (right). Fluorescence intensities along the dashed lines were quantified and plotted on the right side of the images. Scale bars, 100 μm. Epi, epiblast; EXC, extraembryonic ectoderm; EPC, ectoplacental cone; Dc, decidual cells. A.U., arbitrary unit.

(B) Jmjd1a^+/Δ; Jmjd1a^+/Δ males and females were crossed, and the resultant embryos were genotyped at the indicated embryonic periods. Jmjd1a^Δ/Δ; Jmjd1a^Δ/Δ embryos were found at E6.5, but not at E7.5. #, growth-retarded embryos.

(C) Gross appearances of Jmjd1a/Jmjd1b double-deficient embryos at E6.5 (left) when compared with a littermate control (right). 1a and 1b represent Jmjd1a and Jmjd1b, respectively. Scale bar, 100 μm.

(D) Whole-mount immunostaining analysis for the epiblast marker OCT3/4. Embryos were counterstained with DAPI and TUNEL to detect apoptotic cells. Scale bars, 100 μm.

(E) TUNEL-positive cells in the epiblast lineage were counted and summarized. Jmjd1a^+/Δ; Jmjd1a^+/Δ, n = 7; Jmjd1a^Δ/Δ; Jmjd1a^Δ/Δ, n = 3 different embryos (biological replicates). Data are presented as means ± SD. ^∗∗p < 0.01 (Student's t test).