Transgenesis and genome editing in the marine model Platynereis dumerilii

The marine annelid Platynereis dumerilii has emerged as a valuable animal model for a wide range of studies, including evolutionary developmental biology, ecology, and genomics. Our group has recently focused on developing efficient protocols for transgenesis and genome editing in this species. Through modifications to the culture protocol, we have significantly shortened the life cycle of the cultured strain to less than three months, facilitating the maintenance of multiple transgenic strains. We have discovered that Platynereis possesses a robust genomic immunity, capable of suppressing the expression of foreign transgenes. Despite this, we have successfully established the first permanent strain with ubiquitous expression in larval and juvenile cells, indicating the localization of a "safe harbor" for future transgene insertion. Additionally, we have devised an effective protocol for directly inactivating essential genes using CRISPR-Cas9, enabling the genotyping of individual crisprants. These advancements bring Platynereis closer to becoming a unique reverse genetics model for invertebrate marine biology