The power of CRISPR/Cas9 mediated genome editing has been harnessed in different facets of entomological research, particularly useful in developing genetic pest management strategies. The edits thus obtained are robust and results in a loss-of-function of the target gene. Recently the development of newer editing approach called Prime editing is yet another addition in the insect editing tool-box. In this regard, the prime editing offers a transformative approach to precise genome manipulation by enabling targeted insertions, deletions, and nucleotide substitutions without double-strand break or donor template. While its application has been explored in mammalian system and plants, its deployment through the delivery of ribonucleoprotein complex (RNP) has been demonstrated for the first-time in the globally significant pest, Spodoptera frugiperda. Using a Cas9 (H840A)-reverse transcriptase fusion protein (PE2) and a customized prime editing guide RNA (pegRNA), we targeted exon 3 of the Tryptophan 2,3-dioxygenase (SfTO) gene to introduce a premature stop codon. Recombinant PE2 protein was expressed in E. coli, purified, and validated functionally through RT-PCR. The Ribonucleoprotein complex was microinjected into Geggs and subsequent genotyping revealed successful edits, including perfect and imperfect prime edits, as well as unintended mutations. Phenotyping revealed the mutants with altered eye pigmentation, and chromatographic analysis confirmed disruption in ommochrome biosynthesis, validating functional consequences of Prime editing. This study provides a foundational proof-of-concept for Prime editing in insect pests, opening new avenues for functional genomics and designing next-generation pest management strategies. 0
CRISPR Gene Editing