Skip to main content
. 2021 Apr 30;10:e64811. doi: 10.7554/eLife.64811

Figure 1. Rreb1 is expressed within embryonic and extraembryonic tissues.

(A) Wholemount images of Rreb1LacZ/+ mouse embryos from embryonic day (E) 5.5–8.0. Dashed lines mark approximate plane of transverse sections shown in lower panels. Section iii from E7.5 is located in Figure 1—figure supplement 1C. Bracket demarcates the primitive streak. (B) Rreb1LacZ reporter mouse embryonic stem cells (ESCs) (i) and epiblast stem cells (EpiSCs) (ii) under self-renewing conditions. ESCs were grown in serum/LIF on feeders. Panels (iii) and (iv) show ESCs after 7 days of differentiation in the absence of LIF or in the absence of LIF plus 12 ng/ml FGF2. A, anterior; P, posterior; Pr, proximal; Ds, distal; L, left; R, right; EHF, early headfold; ExM, extraembryonic mesoderm; ExVE, extraembryonic visceral endoderm; AVE, anterior visceral endoderm; aEpi, anterior epiblast; Meso, mesoderm; Endo, endoderm; Epi, epiblast; Am, amnion; Al, allantois; Ch, chorion; AxM, axial mesoderm.

Figure 1.

Figure 1—figure supplement 1. Rreb1 expression during mouse embryonic development.

Figure 1—figure supplement 1.

(A) Schematic diagram showing the EUCOMM knockout-first (Tm1a) allele (upper panel) and the Rreb1 null LacZ reporter (Tm1b) allele generated by Cre-mediated recombination of Tm1a (lower panel). Engrailed two splice acceptor (En2 SA), internal ribosome entry side (IRES), human beta actin promoter (hbactP), Neomycin cassette (neo), single polyadenylation sequences (pA), FRT sites (green triangles), loxP sites (orange triangles). (B) Wholemount images of E4.5 Rreb1LacZ/+ blastocysts. (C) Transverse cryosection through a distal region of an E7.5 Rreb1LacZ/+ embryos from Figure 1A. Arrowhead indicates expression within the distal anterior epiblast. Bracket marks the primitive streak/tailbud. (D–F) Wholemount images of Rreb1LacZ/+ embryos. (G) Transverse cryosection of the yolk sac of an E10.5 Rreb1LacZ/+ embryo. (H) Rreb1 expression in different cell types of the early mouse embryo, from published single-cell RNA-sequencing datasets. Left panel: Force-directed layout plot showing relative Rreb1 expression in cells of E3.5–4.5 pre-implantation and E5.5 early post-implantation embryos from single-cell RNA sequencing (scRNA seq.) data. Plot was generated using data from Nowotschin et al., 2019 (https://endoderm-explorer.com/). Right panel: Uniform manifold approximation and projection (UMAP) plot, generated using single-cell sequencing data from Pijuan-Sala et al., 2019 (https://marionilab.cruk.cam.ac.uk/MouseGastrulation2018/), showing Rreb1 expression levels in all the cells at E6.5, 6.75, 7.0, and 7.75. TE, trophectoderm; ICM, inner cell mass; PrE, primitive endoderm; VE, visceral endoderm; ExE, extraembryonic ectoderm; PS, primitive streak; DE, definitive endoderm; Epi, epiblast; Noto, notochord; Meso, mesoderm; NE, neurectoderm; PCP, prechordal plate; Pr, proximal; Ds, distal; A, anterior; P, posterior; L, left; R, right; YS, yolk sac; PA i, pharyngeal arch 1; FNP, frontonasal process; LB, limb bud; IS, isthmus; CM, cephalic mesenchyme.