Figure 6. Id genes are essential for early heart formation. (A) Schematic illustrating the generation and analysis of Id1–4 mutant embryos using CRISPR/Cas9 technology. Two sgRNAs per gene (targeting the translational start site and the HLH domain) were injected into single- cell mouse zygotes alongside Cas9 mRNA. Zygoteswere reimplanted and harvested at stages E7.5–E8.5. Resulting embryos were genotyped by DNA deep sequencing, and cardiac gene expression was assessed via whole-mount in situ hybridization. (B–U) In situ hybridization results from the most severe Id1–4 mutants—compared with wild type (individual mutants are marked by #)—plus one less-affected mutant (O); analysis of Smarcd3 at E7.75 (B–E), Tbx5 at E8.0 (F–I), Nkx2.5 at E8.25 (J–M; plus transverse sections through the heart tube-forming region [K′,M′]), Nkx2.5 at E8.5 (N–Q), and Tbx5 at E8.5 (R–U). (Yellow arrowheads) Missing heart tube (or missing heart tube-forming region at cardiac crescent stages) in Id1–4 mutants; (white arrowhead) malformed heart tube; (black arrows) the plane of transverse sectioning through the heart tube-forming region; (black dashed arrows) posterior–lateral cardiac regions. See the Supplemental Material for detailed sequencing results of mutant embryos.
Image published in: Cunningham TJ et al. (2017)
Copyright © 2017. Image reproduced on with permission of the Publisher, Cold Spring Harbor Laboratory Press. This is an Open Access article distributed under the terms of the Creative Commons Attribution License.
Permanent Image Page
Printer Friendly View
XB-IMG-173442