Inactivation of Sebol Induces Male Infertility in Spodoptera exigua via Arrested Meiosis: A Potential Molecular Target for Genetics-Based Sterile Insect Technique

The beet armyworm, Spodoptera exigua, is a significant agricultural pest managed primarily through chemical insecticides, which present environmental concerns and promote resistance. Genetics-based sterile insect technique (gSIT) provides an alternative by inducing male sterility without irradiation. In this study, we cloned the S. exigua boule gene (Sebol), a 741-nucleotide open reading frame encoding a 246-amino-acid protein with an RNA recognition motif. Phylogenetic analysis confirmed its conservation across Lepidoptera and high similarity to orthologs in Spodoptera litura and Helicoverpa armigera. Sebol is predominantly expressed in adult males, particularly in the testis. CRISPR/Cas9-mediated deletion of 190 bp in exon 1 generated a truncated Sebol protein, resulting in complete male sterility. Transcriptome analysis revealed 2069 differentially expressed genes associated with sperm development, with potential interactions involving syf1 and ZNFX1. Our findings suggest that Sebol is crucial for spermatogenesis, making it a promising target for gSIT-based pest control.