In this study, a novel β-1,3-glucan recognition protein gene (β-GRP) was identified from Melanotus cribricollis, and its potential role in the immune response was investigated. The full length of β-GRP cDNA (Accession Number: MT941530) was 1644 bp, encoding a protein composed of 428 amino acids. The theoretical molecular weight and the isoelectric point were 51.53 kDa and 6.17, respectively. The amino acid sequence of β-GRP from M. cribricollis was closely related to that of. β-GRP-like from Photinus pyralis, and was predicted to contain conserved GH16 domain without glucanase active site. The results of real-time quantitative PCR showed that fungal infection of Metarhizium pingshaense may significantly upregulated the expression level of β-GRP gene. The RNAi suppression of β-GRP gene expression significantly increased the corrected cumulative mortality. Meanwhile, antimicrobial peptide genes defensin and lysozyme were significantly downregulated after interference of β-GRP. Taken together, these results suggest that β-GRP of M. cribricollis probably participates in the host immune system by mediating the expression of antimicrobial peptides. This study provides comprehensive insights into the innate immune system of insect larvae.

中文翻译：

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一种新的 β-GRP 基因的克隆和功能表征

在这项研究中，从黑斑蝽中鉴定出一种新的β-1,3-葡聚糖识别蛋白基因（β-GRP），并研究了其在免疫反应中的潜在作用。β-GRP cDNA（登录号：MT941530）全长1644 bp，编码428个氨基酸组成的蛋白质。理论分子量和等电点分别为51.53 kDa和6.17。M. cribricollis的β-GRP氨基酸序列与其密切相关。来自 Photinus pyralis 的 β-GRP 样，预计含有保守的 GH16 结构域，没有葡聚糖酶活性位点。实时定量PCR结果表明，真菌感染平沙绿僵菌可显着上调β-GRP基因表达水平。β-GRP 基因表达的 RNAi 抑制显着增加了校正的累积死亡率。同时，β-GRP干扰后抗菌肽基因防御素和溶菌酶显着下调。总之，这些结果表明 M. cribricollis 的 β-GRP 可能通过介导抗菌肽的表达参与宿主免疫系统。这项研究为昆虫幼虫的先天免疫系统提供了全面的见解。