CRISPR-Cas9 Gene Editing in Lizards Through Microinjection of Unfertilized Oocytes

Summary: CRISPR-Cas9-mediated gene editing has enabled the direct manipulation of gene function in many species. However, the reproductive biology of reptiles presents unique barriers for the use of this technology, and there are no reptiles with effective methods for targeted mutagenesis. Here, we demonstrate that the microinjection of immature oocytes within the ovaries of Anolis sagrei females enables the production of CRISPR-Cas9-induced mutations. This method is capable of producing F0 embryos and hatchlings with monoallelic or biallelic mutations. We demonstrate that these mutations can be transmitted through the germline to establish genetically modified strains of lizards. Direct tests of gene function can now be performed in Anolis lizards, an important model for studies of reptile evolution and development. : The reproductive biology of reptiles makes accessing single-cell embryos difficult and presents a major barrier for deploying gene-editing technologies in these species. Rasys et al. report that the microinjection of Cas9 RNP into immature lizard oocytes enables the production of lizards with targeted mutations. Keywords: Anolis, lizard, CRISPR, Cas9, gene editing, reptile, oocyte, tyrosinase