Identification and evaluation of two testis‐specific serine/threonine kinase genes from multi‐tissue transcriptomes as potential genetic targets of sterile insect technique in Zeugodacus tau

BACKGROUND: Zeugodacus tau (Walker) is a notorious agricultural pest causing significant economic losses in vegetable production for many years. Sterile insect technique (SIT) has emerged as an environmentally sustainable pest management strategy. However, discovery of molecular targets applicable for SIT implementation in Z. tau still constitutes a significant research gap. RESULTS: We conducted comparative transcriptome analysis of four male tissues (midgut, Malpighian tubules, fat body, and testis), identifying 9653 differentially expressed genes (DEGs) with predominant testis enrichment. Bioinformatics screening revealed 3020 testis-specific highly expressed genes showing significant functional enrichment in cytoplasmic translation, cytosolic ribosome assembly, and oxidoreductase activity. Quantitative real-time PCR (qRT-PCR) assay was utilized to confirm 10 testis-specific genes, including two serine/threonine kinases (ZtTSSK1 and ZtTSSK3) which were significantly enriched in spermatid development. Fluorescence in situ hybridization (FISH) localized the two genes specifically to the transformation zone of Z. tau testis. Functional characterization via RNAi bioassay demonstrated that suppression of ZtTSSKs expression levels reduced spermatozoa number and impaired male fertility. CONCLUSION: These results establish ZtTSSKs as crucial regulators of male fertility in Z. tau and identify them as potential molecular targets for developing SIT-based interventions against this economically significant pest. © 2026 Society of Chemical Industry.