State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China.
Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, China.
BMC Biol. 2022 Jul 6;20(1):157. doi: 10.1186/s12915-022-01356-6.
Hoverflies (Diptera: Syrphidae) including Eupeodes corollae are important insects worldwide that provide dual ecosystem services including pest control and pollination. The larvae are dominant predators of aphids and can be used as biological control agents, and the adults are efficient pollinators. The different feeding habits of larvae and adults make hoverflies a valuable genetic resource for understanding the mechanisms underlying the evolution and adaptation to predation and pollination in insects.
Here, we present a 595-Mb high-quality reference genome of the hoverfly E. corollae, which is typical of an aphid predator and a pollinator. Comparative genomic analyses of E. corollae and Coccinellidae (ladybugs, aphid predators) shed light on takeout genes (3), which are involved in circadian rhythms and feeding behavior and might regulate the feeding behavior of E. corollae in a circadian manner. Genes for sugar symporter (12) and lipid transport (7) related to energy production in E. corollae had homologs in pollinator honeybees and were absent in predatory ladybugs. A number of classical cytochrome P450 detoxification genes, mainly CYP6 subfamily members, were greatly expanded in E. corollae. Notably, comparative genomic analyses of E. corollae and other aphidophagous hoverflies highlighted three homologous trypsins (Ecor12299, Ecor12301, Ecor2966). Transcriptome analysis showed that nine trypsins, including Ecor12299, Ecor12301, and Ecor2966, are strongly expressed at the larval stage, and 10 opsin genes, which are involved in visual perception, are significantly upregulated at the adult stage of E. corollae.
The high-quality genome assembly provided new insights into the genetic basis of predation and pollination by E. corollae and is a valuable resource for advancing studies on genetic adaptations and evolution of hoverflies and other natural enemies.
食蚜蝇（双翅目：食蚜蝇科）包括欧洲食蚜蝇，是全世界重要的昆虫，提供害虫控制和授粉的双重生态系统服务。幼虫是蚜虫的主要捕食者，可作为生物防治剂，成虫是有效的授粉者。幼虫和成虫的不同取食习性使食蚜蝇成为研究昆虫捕食和授粉进化适应机制的宝贵遗传资源。
本研究提供了一种高质量的 595Mb 欧洲食蚜蝇参考基因组，该基因组是典型的蚜虫捕食者和授粉者。欧洲食蚜蝇与瓢虫（蚜虫捕食者）的比较基因组分析揭示了取食相关基因（3），这些基因参与昼夜节律和取食行为，可能以昼夜节律方式调节欧洲食蚜蝇的取食行为。与能量产生相关的糖转运体（12）和脂质转运体（7）基因在欧洲食蚜蝇中有同源物，而在捕食性瓢虫中则没有。大量经典细胞色素 P450 解毒基因，主要是 CYP6 亚家族成员，在欧洲食蚜蝇中得到了极大的扩展。值得注意的是，欧洲食蚜蝇与其他食蚜性食蚜蝇的比较基因组分析突出了三种同源的胰蛋白酶（Ecor12299、Ecor12301 和 Ecor2966）。转录组分析表明，包括 Ecor12299、Ecor12301 和 Ecor2966 在内的 9 种胰蛋白酶在幼虫期强烈表达，而参与视觉感知的 10 种视蛋白基因在欧洲食蚜蝇成虫期显著上调。
高质量的基因组组装为研究欧洲食蚜蝇的捕食和授粉的遗传基础提供了新的见解，是推进食蚜蝇和其他天敌遗传适应和进化研究的宝贵资源。
