Reck shRNA interferes with vascular remodeling in the mouse implantation chamber. (A) The site of bead injection (red line) in the mesometrial area at 5 dpc. (B) Control experiments to assess the efficiency of gelatin-bead-mediated gene transfer into the implantation chamber. Cationized gelatin beads impregnated with a LacZ-expression vector were injected into the mesometrial area at 5 dpc, and tissue slices were prepared at 10 dpc and stained with X-gal. A typical image is shown. (C) Mesometrial tissue at 10 dpc that had been transfected on 5 dpc with a plasmid expressing either LacZ (panels 1, 2) or shRNA against Reck (sh-1; panels 3, 4) was sliced and stained with H&E (panels 1, 3) or immunostained for type IV collagen (panels 2, 4). The yellow double-headed arrows indicate the DB, and the black arrows abnormal vessels. (D) The frequency of samples with abnormal decidua after transfection with vectors expressing LacZ or either of the two shRNA against Reck, sh-1 and sh-2, with different efficacy. Embryos were scored abnormal when the vessels in the transfected areas were severely disrupted as shown in panels 3 and 4 in C; the abnormality was often accompanied by reduced cellularity in the areas as well. Bar represents mean ± s.e.m., n = 7 pregnant mice. Total implantation chambers tested: LacZ, 81; sh-1, 88; sh-2, 86. Student's t-test: LacZ vs. sh-1, p = 1.7 × 10-8; LacZ vs. sh-2, p = 1.4 × 10-5; sh-1 vs. sh-2, p = 1.6 × 10-5. Scale bar: B, 200 μm; C, 100 μm.