Background: Male-biased silkworm larva resistance is useful for sericulture and lepidopteran pest control. According to previous research, the mechanism underlying this resistance might be related to midgut-specific proteins.
Results: A midgut-specific and novel hypothetical cuticular protein-like (Cph-like) gene was cloned, based on sex-disparity serial analysis of gene expression (SAGE) libraries of the B. mori midgut. The complete cDNA contained 676 bp and encoded 165 amino acid residues. The gene was located on chromosome 19 and it had only one short 75 bp intron. The Cph-like expression level was downregulated by exogenous 20-hydroxyecdysone or starvation, but upregulated by exogenous methoprene or food intake. Knockdown (siRNA) of the Cph-like gene suppressed the appetite and delayed larval development, while it also degraded enterocytes and damaged the midgut morphology. Furthermore, the male-biased cytoplasmic polyhedrosis virus (BmCPV) resistance of larvae was decreased.
Conclusion: The Cph-like gene is a midgut-specific novel gene in B. mori that may participate in histogenesis and midgut maintenance.
Keywords: BmCPV resistance; Bombyx mori; gene expression; hypothetical cuticular protein.
© 2013 Society of Chemical Industry.