Analysis of the genome-editing activity of microinjected CRISPR/Cas9 ribonucleoprotein complexes in Daphnia pulex.

Although Daphnia is a widely used model organism with a completely sequenced genome, molecular tools for analyzing specific gene functions are still being developed. Progress has been made in developing CRISPR/Cas9 gene editing in Daphnia . However, the gene-editing activity of injected ribonucleoprotein complexes (RNPs), the success of co-injected RNPs with different gRNAs, and the heritability of mutations in asexual progeny need further investigation. Here, we show prolonged Cas9 RNP activity past the one-cell stage injected individuals, leading to a wide range of somatic mutations, and germline mosaicism of heritable biallelic mutations.