昆虫学报 ›› 2020, Vol. 63 ›› Issue (8): 924-931.doi: 10.16380/j.kcxb.2020.08.002

• 研究论文 • 上一篇    下一篇

fruitless在桔小实蝇求偶和交配行为中的作用

陈瑶瑶1,2, 古枫1,2, 钟国华1,2,*, 易欣1,2,*   

  1. (1. 华南农业大学农学院, 农业农村部华南作物有害生物综合治理重点实验室, 广州 510642; 2. 华南农业大学农学院, 天然农药与化学生物学教育部重点实验室, 广州 510642)
  • 出版日期:2020-08-20 发布日期:2020-09-09

Role of fruitless in courtship and mating behaviors in Bactrocera dorsalis (Diptera: Tephritidae)

CHEN Yao-Yao1,2, GU Feng1,2, ZHONG Guo-Hua1,2,*, YI Xin1,2,*   

  1.  (1. Key Laboratory of Integrated Pest Management of Crop in South China, Ministry of Agriculture, College of Agriculture, South China Agricultural University, Guangzhou 510642, China; 2. Key Laboratory of Natural Pesticide and Chemical Biology, Ministry of Education, College of Agriculture, South China Agricultural University, Guangzhou 510642, China)
  • Online:2020-08-20 Published:2020-09-09

摘要: 【目的】fruitless (fru)是昆虫求偶和交配行为中的关键基因,但是其在桔小实蝇Bactrocera dorsalis中的具体功能尚不清楚。本研究旨在明确fru在桔小实蝇求偶交配行为中的作用,进一步明确fru的生物学意义。【方法】根据NCBI上桔小实蝇fru的预测序列设计两端引物,以桔小实蝇羽化10 d已交配的成虫头部cDNA为模板克隆fru基因的全长cDNA,并对其编码蛋白的结构域进行预测。通过实时荧光定量PCR(RT-qPCR)技术检测该基因在桔小实蝇交配前后表达量的变化。待合成fru基因的dsRNA后,注射到羽化9 d后的桔小实蝇雄成虫腹部进行RNAi,分别于注射后48 h和72 h取样,检测fru基因的相对表达量;并于RNAi后72 h进行求偶交配行为观察,测定桔小实蝇的交配频率和交配持续时间。【结果】克隆获得桔小实蝇fru的全长cDNA,长2 865 bp,编码954个氨基酸,预测蛋白分子量104.1 kD,等点为6.01。该基因所编码的蛋白具有特殊结构域,分别为一个BTB (Broad-complex, Tramtrack and Bric-a-bric)结构域和两个锌指(zinc finger)结构域。RT-qPCR结果表明,相比未交配的桔小实蝇成虫,fru基因在雄成虫头部中的表达量在与雌成虫交配后显著上升。相对于空白对照组(注射DEPC水)和阴性对照组(注射dsGFP),注射dsfru的RNAi处理组的雄性求偶时间延长(延长了25~35 min),且交配频率下降(降低了17%~22%),说明fru基因在雄性桔小实蝇的求偶交配行为中发挥着重要作用。【结论】本研究结果为明确fru在非模式昆虫桔小实蝇求偶交配行为中的功能提供参考,并为深入研究桔小实蝇的求偶交配行为和绿色防控提供了理论基础。

关键词: 桔小实蝇; fruitless, 表达谱, 求偶行为, 交配频率, RNAi

Abstract: 【Aim】 fruitless (fru) is the key gene for courtship and mating behaviors in insects, but its specific role in Bactrocera dorsalis is still unclear. The aim of this study is to characterize the role of fru in courtship and mating behaviors in B. dorsalis and to further clarify its biological significance. 【Methods】 Primers were designed based on the fru sequence of B. dorsalis from NCBI, the full-length cDNA of fru gene was cloned from the head of the mated 10-day-old adults of B. dorsalis, and the structural domain of its encoded protein was predicted. The variations of gene expression levels in B. dorsalis adults before and after mating were analyzed by real-time fluorescent quantitative PCR (RT-qPCR). The fru dsRNA was synthesized, and injected into the abdomen of the 9-day-old adults. The relative expression level of fru was examined at 48 and 72 h after injection. At 72 h after injection, the courtship and mating behaviors including the mating frequency and duration were examined. 【Results】 The full-length cDNA of B. dorsalis fru obtained by cloning is 2 865 bp in length, encoding 954 amino acids with the predicted molecular weight of 104.1 kD and pI of 6.01. The encoded protein has unique domains including one BTB domain and two zinc finger domains. The RT-qPCR results revealed that the expression level of fru in the head of male adults of B. dorsalis was significantly higher after mating than before mating. B. dorsalis male adults in the RNAi group injected with dsfru engaged significantly longer time (25-35 min longer) in the courtship behavior and had the mating frequency decreased by 17%-22% as compared to the male adults in the blank control group (injected with DEPC water) and the negative control group (injected with dsGFP), suggesting that fru plays important roles in regulating courtship and mating behaviors of male B. dorsalis. 【Conclusion】 The results of this study provide a theoretical basis for clarifying the role of fru in the non-model insect B. dorsalis and further studying courtship and mating behaviors in B. dorsalis.

Key words: Bactrocera dorsalisfruitless, expression profile, courtship behavior, mating frequency, RNAi