Fig. 6.

AGS, Gαi, and Vasa proteins are enriched in micromere-like cells of the pencil urchin embryo but not in the sea star embryo. a Immunofluorescence images of AGS (green) and Gαi (red) in sea star embryos. No specific signal was found in any region of the cortex during early embryogenesis in over 90% of embryos, n < 50. b, d Immunofluorescence images of pencil urchin embryos. In b, at 8 and 16 cell stages, embryos were enriched in AGS and Gαi at the vegetal cortex (arrows). These proteins were also enriched within the cytoplasm of the vegetal blastomeres or micromere-like cells in some embryos. Embryos lacking micromere-like cells also lacked AGS and Gαi enrichment on the cortex. n = 20. In c AGS was localized to the centrosomes in addition to the cortex, similar to that of sea urchin (S. purpuratus). n = 10. In d, Vasa (green) was enriched in the cytoplasm of the micromere-like cells, and enrichment was absent when micromere-like cells were not present. n = 15. The representative phenotypes of 80% or larger in each population are shown. Each experiment was performed at least two independent times. Scar bars = 10 μm