Efficient CRISPR-mediated genome editing can be initiated by embryonic injection but not by ovarian delivery in the beetle Tribolium castaneum.

The clustered regularly interspaced small palindromic repeats (CRISPR) / CRISPR-associated nuclease 9 (Cas9)-mediated gene editing technology has revolutionized the study of fundamental biological questions in various insects. Diverse approaches have been developed to deliver the single-guide RNA (sgRNA) and Cas9 to the nucleus of insect embryos or oocytes to achieve gene editing, including the predominant embryonic injection methods and alternative protocols through parental ovary delivery. However, a systematic comparative study of these approaches is limited, especially within a given insect.