Eicosanoids mediate sHSP 20.8 gene response to biotic stress in larvae of the Chinese oak silkworm Antheraea pernyi

• A small heat shock protein 20.8 was first identified in A. pernyi.
• The expression of Ap-sHSP20.8 was abundant in the midgut and fat body.
• AP-sHSP20.8 was obviously induced by microorganism challenges.
• Eicosanoids could mediate the induction of Ap-sHSP20.8 in the fat body and midgut.

Small heat shock proteins (sHSPs) can regulate protein folding and protect cells from stress. To investigate the role of sHSPs in the silk-producing insect Antheraea pernyi (A. pernyi; Lepidoptera: Saturniidae), cDNA encoding HSP20.8 in A. pernyi, termed Ap-sHSP20.8, was identified as a 564 bp ORF. The translated amino acid sequence encoded 187 residues with a calculated molecular mass of 20.8 kDa and an isoelectronic point (pI) of 5.98; the sequence showed homology to sHSP chaperone proteins from other insects. Ap-sHSP20.8 mRNA transcript expression was abundant in the midgut and fat body and found to be both constitutive and inducible by infectious stimuli. Therefore, Ap-sHSP20.8 may play important roles in A. pernyi immune responses under biotic stress. Furthermore, we found that eicosanoids could mediate the induction of Ap-sHSP20.8 in the fat body and midgut. Our findings show that sHSPs may be promising molecules to target in order to cripple immunity in insect pests.