State Key Laboratory of Biocontrol and School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, Guangdong, China.
State Key Laboratory of Rice Biology, Institute of Insect Sciences, Zhejiang University, Hangzhou, 310029, Zhejiang, China.
BMC Genomics. 2018 Dec 27;19(1):970. doi: 10.1186/s12864-018-5391-5.
The insect gustatory system plays a central role in the regulation of multiple physiological behaviors and the co-evolution between insects and their hosts. The gustatory receptors (Gr) are important to allow insects to sense their environment. It is critical to the selection of foods, mates and oviposition sites of insects. In this study, the Gr family genes of the brown planthopper (BPH) Nilaparvata lugens Stål (Hemiptera: Delphacidae) were identified and analyzed, and their potential relationship to the fecundity of BPH was explored by RNA interference (RNAi).
We identified 32 putative Gr genes by analyzing transcriptome and genome data from BPH. Most of these Gr proteins have the typical structure of seven transmembrane domains. The BPH Gr genes (NlGrs) were expressed in virtually all tissues and stages, whilst higher transcript accumulations were found in adult stages and in the midguts of females. Based on the phylogenic analysis, we classified NlGrs into five potential categories, including 2 sugar receptors, 2 Gr43a-like receptors, 7 CO receptors, 5 bitter receptors and 13 NlGrs with unknown functions. Moreover, we found that 10 NlGrs have at least two alternative splicing variants, and obtained alternative splicing isoforms of 5 NlGrs. Finally, RNAi of 29 NlGrs showed that 27 of them are related to the transcript levels of two fecundity related genes vitellogenin and vitellogenin receptor.
We found 32 Gr genes in BPH, among which at least 27 are required for normal expression of fecundity markers of this insect pest. These findings provide the basis for the functional study of Grs and the exploration of potential genes involved in the monophagous character of BPH.
昆虫味觉系统在调节多种生理行为以及昆虫与其宿主的共同进化中起着核心作用。味觉受体（Gr）对于昆虫感知环境至关重要。它对昆虫选择食物、配偶和产卵场所至关重要。本研究通过 RNA 干扰（RNAi）鉴定和分析褐飞虱（BPH）Nilaparvata lugens Stål（半翅目：飞虱科）的 Gr 家族基因，并探讨其与 BPH 繁殖力的潜在关系。
通过分析 BPH 的转录组和基因组数据，我们鉴定了 32 个推定的 Gr 基因。这些 Gr 蛋白大多数具有七个跨膜结构域的典型结构。BPH Gr 基因（NlGrs）在几乎所有组织和阶段都有表达，而在成虫阶段和雌性中肠中发现更高的转录积累。根据系统发育分析，我们将 NlGrs 分为五个潜在类别，包括 2 个糖受体、2 个 Gr43a 样受体、7 个 CO 受体、5 个苦味受体和 13 个具有未知功能的 NlGrs。此外，我们发现 10 个 NlGrs 至少有两个选择性剪接变体，并获得了 5 个 NlGrs 的选择性剪接异构体。最后，29 个 NlGrs 的 RNAi 表明，其中 27 个与两种繁殖力相关基因卵黄原蛋白和卵黄原蛋白受体的转录水平有关。
我们在 BPH 中发现了 32 个 Gr 基因，其中至少 27 个基因对于这种害虫繁殖力标志物的正常表达是必需的。这些发现为 Grs 的功能研究和探索 BPH 单食性特征的潜在基因提供了基础。
