Small heat shock proteins are a molecular chaperone and implicated in various physiological and stress processes in animals. However, the immunological functions of Hsp genes remain to elucidate in the crustaceans, particularly in red swamp crayfish, Procambarus clarkii. Here we report the cloning of heat shock protein 21 from the P. clarkii (hereafter Pc-Hsp21). The open reading frame of Pc-Hsp21 was 555 base pairs, encoding a protein of 184 amino acid residues with an alpha-crystallin family domain. Quantitative real-time PCR (qRT-PCR) analysis revealed a constitutive transcript expression of Pc-Hsp21 in the tested tissue, with the highest in hepatopancreas. The transcript abundance for this gene enhanced in hepatopancreas following immune challenge with the lipopolysaccharide, peptidoglycan, and poly I:C compared to the control group. The depletion of Pc-Hsp21 by double-stranded RNA altered transcript expression profiles of several genes in hepatopancreas, genes involved in the crucial immunological pathways of P. clarkii. These results suggest that Pc-Hsp21 plays an essential biological role in the microbial stress response by modulating the expression of immune-related genes in P. clarkii.

小热休克蛋白是一种分子伴侣，与动物的各种生理和应激过程有关。然而，Hsp 基因的免疫功能在甲壳类动物中仍有待阐明，特别是在红沼泽小龙虾Procambarus clarkii 中。在这里，我们报告了从P. clarkii (以下简称Pc-Hsp21 )克隆热休克蛋白 21 。Pc-Hsp21的开放阅读框是 555 个碱基对，编码 184 个氨基酸残基的蛋白质，具有 α-晶状体蛋白家族结构域。定量实时 PCR (qRT-PCR) 分析揭示了Pc-Hsp21的组成型转录物表达在被测组织中，以肝胰腺最高。与对照组相比，在用脂多糖、肽聚糖和聚 I:C 进行免疫攻击后，该基因在肝胰腺中的转录丰度增加。双链 RNA对Pc-Hsp2 1的消耗改变了肝胰腺中几个基因的转录表达谱，这些基因参与了克拉氏疟原虫的关键免疫途径。这些结果表明Pc-Hsp21通过调节P. clarkii中免疫相关基因的表达，在微生物应激反应中发挥重要的生物学作用。