In vivo localization of NvPar-6::mVenus during different stages of N. vectensis development. The overexpressed NvPar-6::mVenus protein (A) displays similar patterns observed with the antibody staining against the same protein, and no signal was observed in the endoderm. Co-injection with Lifeact::mTq2 mRNA (B) shows the shape of the cells and their apical cortex. Similar to NvaPKC::mVenus, NvPar-6::mVenus is below the cortical actin during all observed stages (C). White arrows indicate astral/centrosomal and (pro)nuclear structures. White arrowheads indicate the locations adjacent to other cells (cell contacts) where NvPar-6::mVenus is localized. Images of unfertilized, cleavage, and side panels in gastrula stages correspond to a single slice from z-stack series. Image of the whole blastula and gastrula corresponds to a 3D reconstruction from z-stack series. Side panels in blastula and gastrula stages are a mid section from the z-stack series to show the apical distribution of NvPar-6::mVenus along the A/B axis. Additional files 10, 11, 12, 13, and 14 for more details of every stage presented here in C.