MZmarcksb showed genetic compensation on BMP signaling.
(A, B) Injection of marcksb_MO in MZmarcksb did not cause defect of dorsalization. (A) morphological observation of MZmarcksb and marcksb_MO injected MZmarcksb. Up panels, field view of embryos at 12 hpf; lower panels, representative embryos at 30 hpf. (B) WISH analysis showed that the transcriptional levels of downstream targets of BMP signaling—szl and ved were at comparable level between MZmarcksb and marcksb_MO injected MZmarcksb. (C) The overall intensity of p-Smad1/5/9 at ventral region in MZmarcksb was slightly increased when compared with wildtype. (D) The normalized fluorescent intensity of P-Smad1/5/9. Error bars of light blue and light red show S.E.M. (E) The extracellular mCherry-Bmp2b was slightly increased in the MZmarcksb compared with wildtype embryos. (F) Quantitative measurement of secreted Bmp2b in wildtype and MZmarcksb embryos. The data were presented as scatter plots with median; *”: P < 0.01, from Student’s t-test. (G) Although knockdown of chd in wildtype embryos only resulted in moderate ventralization (V1-V2), knockdown of chd in MZmarcksb embryos resulted in severe ventralization (V3-V4). V1-V4, ventralization type 1 to type 4 embryos; the statistical data are shown in the bar graphs with the number of observed embryos indicated right. (H) After injection of chd_MO, the up-regulation of BMP signaling activity was much more robust in MZmarcksb than that in wildtype embryos shown by WISH analysis of szl (a vs b) and ved (c vs d). The embryos are at shield stage and animal-pole view with dorsal to the right; (I) The percentage of embryos with normal-like, increased, and dramatically-increased expression of szl and ved. “n” represents the number of embryos we observed.