Peptidoglycan recognition proteins (PGRPs) contribute to the immune response of vertebrates and higher invertebrates. Animals have a varying number of PGRP genes: 4 in human and mouse, 13 in Drosophila, and 0 in an aphid. Transcriptome analyses revealed that numerous PGRP genes (> 300 in an RNA-Seq analysis) were expressed in the green rice leafhopper Nephotettix cincticeps (Uhler) (Hemiptera, Cicadellidae). PGRP genes were mostly expressed in the bacteriomes, in which two bacterial endosymbionts, Sulcia and Nasuia, are harbored. E. coli inoculation upregulated antimicrobial peptide gene expression in the leafhopper, whereas PGRP gene expression was not affected by the bacterial challenge. High and constant expression of PGRP genes in the bacteriomes and the lack of an immune response against invading bacteria suggest that these PGRPs play a hitherto unknown role in the bacteriomes, implicating a relationship with symbiotic association in N. cincticeps.

中文翻译：

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在绿色稻叶蝉 Nephotettix cincticeps（半翅目，蝉科）的细菌组中表达了许多肽聚糖识别蛋白基因

肽聚糖识别蛋白 (PGRP) 有助于脊椎动物和高等无脊椎动物的免疫反应。动物具有不同数量的 PGRP 基因：人类和小鼠中有 4 个，果蝇中有 13 个，蚜虫中有 0 个。转录组分析显示，许多 PGRP 基因（在 RNA-Seq 分析中 > 300）在绿色稻叶蝉 Nephotettix cincticeps (Uhler)（半翅目，蝉科）中表达。PGRP 基因主要在细菌组中表达，其中包含两种细菌内共生体 Sulcia 和 Nasuia。大肠杆菌接种上调叶蝉中的抗菌肽基因表达，而 PGRP 基因表达不受细菌攻击的影响。