In vivo embryonic localization of NvPar-6::mVenus and NvLgl::mCherry during different stages of N. vectensis development. Co-injection of NvPar-6::mVenus (A) and NvLgl::mCherry (B) confirms our observations for the localization of both proteins through separate experimental approaches. Throughout N. vectensis development, both proteins separate into distinct domains (C). Lifeact::mTq2 mRNA (D) was used to visualize the shape of the cells and the apical cortex. NvPar-6::mVenus and NvLgl::mCherry were always observed below the cortical actin during all observed stages (E). Images of cleavage and blastula stages correspond to a single slice from z-stack series. Images of the gastrula stage correspond to a 3D reconstruction from z-stack series. See Additional files 27, 28, 29, and 30 and Figure 11 for more details of every stage presented here.