CRISPR-based Genome Editing of a Diurnal Rodent, Nile Grass Rat ( Arvicanthis niloticus) .

Diurnal and nocturnal mammals have evolved distinct pathways to optimize survival for their chronotype-specific lifestyles. Conventional rodent models, being nocturnal, may not sufficiently recapitulate the biology of diurnal humans in health and disease. Although diurnal rodents are potentially advantageous for translational research, until recently, they have not been genetically tractable. Here, we address this major limitation by demonstrating the first successful CRISPR genome editing of the Nile grass rat ( ), a valuable diurnal rodent. We establish methods for superovulation; embryo development, manipulation, and culture; and pregnancy maintenance to guide future genome editing of this and other diurnal rodent species.