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

The beet armyworm, <i>Spodoptera exigua</i>, 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 <i>S. exigua</i> boule gene (<i>Sebol</i>), 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 <i>Spodoptera litura</i> and <i>Helicoverpa armigera</i>. <i>Sebol</i> 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 <i>syf1</i> and <i>ZNFX1</i>. Our findings suggest that <i>Sebol</i> is crucial for spermatogenesis, making it a promising target for gSIT-based pest control.