The evolutionary modifications of a GoLoco motif in the AGS protein facilitate micromere formation in the sea urchin embryo

• DOI: 10.7554/elife.100086.2
• Publication Date: 2024-11-29T11:25:10Z
• Authors: Natsuko Emura; Florence DM Wavreil; Annaliese Fries; Mamiko Yajima
• Keywords: Motif (music)

The evolutionary introduction of asymmetric cell division (ACD) into the developmental program facilitates formation a new type, contributing to diversity and, eventually, species diversification. micromere sea urchin embryo may serve as one those examples: An ACD at 16-cell stage forms micromeres unique echinoids among echinoderms. We previously reported that polarity factor, Activator G-protein Signaling (AGS), plays crucial role in formation. However, AGS and its associated factors are present all echinoderms across most metazoans. This raises question what modifications protein or surrounding molecular environment contributed acquisition only echinoids. In this study, we learned GoLoco motifs C-terminus play critical roles regulating embryos. Further, other echinoderms’ chimeric contain orthologs from various organisms showed varied localization function contrast, star pencil were consistently localized vegetal cortex embryo, suggesting be variable factor Consistently, appears facilitate micromere-like accelerate enrichment timing germline Vasa during early embryogenesis urchin, an ancestral type urchin. Based on these observations, propose evolution single while preserving core machinery beyond evolution.