State Key Laboratory of Biocontrol, School of Life Sciences / School of Ecology, Sun Yat-sen University, Guangzhou, Guangdong, China.
School of Biological Sciences, University of Queensland, Brisbane, Queensland, Australia.
BMC Genomics. 2022 Jan 31;23(1):90. doi: 10.1186/s12864-022-08299-w.
Members of the genus Novius Mulsant, 1846 (= Rodolia Mulsant, 1850) (Coleoptera, Coccinellidae), play important roles in the biological control of cotton cushion scale pests, especially those belonging to Icerya. Since the best-known species, the vedalia beetle Novius cardinalis (Mulsant, 1850) was introduced into California from Australia, more than a century of successful use in classical biological control, some species of Novius have begun to exhibit some field adaptations to novel but related prey species. Despite their economic importance, relatively little is known about the underlying genetic adaptations associated with their feeding habits. Knowledge of the genome sequence of Novius is a major step towards further understanding its biology and potential applications in pest control.
We report the first high-quality genome sequence for Novius pumilus (Weise, 1892), a representative specialist of Novius. Computational Analysis of gene Family Evolution (CAFE) analysis showed that several orthogroups encoding chemosensors, digestive, and immunity-related enzymes were significantly expanded (P < 0.05) in N. pumilus compared to the published genomes of other four ladybirds. Furthermore, some of these orthogroups were under significant positive selection pressure (P < 0.05). Notably, transcriptome profiling demonstrated that many genes among the significantly expanded and positively selected orthogroups, as well as genes related to detoxification were differentially expressed, when N. pumilus feeding on the nature prey Icerya compared with the no feeding set. We speculate that these genes are vital in the Icerya adaptation of Novius species.
We report the first Novius genome thus far. In addition, we provide comprehensive transcriptomic resources for N. pumilus. The results from this study may be helpful for understanding the association of the evolution of genes related to chemosensing, digestion, detoxification and immunity with the prey adaptation of insect predators. This will provide a reference for future research and utilization of Novius in biological control programs. Moreover, understanding the possible molecular mechanisms of prey adaptation also inform mass rearing of N. pumilus and other Novius, which may benefit pest control.
Novius Mulsant，1846 属（= Rodolia Mulsant，1850）（鞘翅目，瓢虫科）的成员在棉花垫状蚧虫害的生物防治中起着重要作用，特别是那些属于 Icerya 的成员。自从最著名的物种，vedalia 甲虫 Novius cardinalis（Mulsant，1850）从澳大利亚引入加利福尼亚以来，一个多世纪以来在经典生物防治中的成功应用，一些 Novius 物种已经开始表现出一些对新的但相关的猎物物种的野外适应。尽管它们具有经济重要性，但对与其饮食习惯相关的潜在遗传适应知之甚少。对 Novius 基因组序列的了解是进一步了解其生物学和在害虫防治中潜在应用的重要一步。
我们报告了 Novius pumilus（Weise，1892）的第一个高质量基因组序列，Novius pumilus 是 Novius 的代表专家。基因家族进化的计算分析（CAFE）分析表明，与其他四种瓢虫的已发表基因组相比，编码化学感受器、消化和免疫相关酶的几个直系同源物显著扩张（P < 0.05）。此外，其中一些直系同源物受到显著的正选择压力（P < 0.05）。值得注意的是，当 N. pumilus 以自然猎物 Icerya 为食时，与不进食组相比，许多显著扩张和正选择的直系同源物中的基因以及与解毒相关的基因的转录组谱显示出差异表达。我们推测，这些基因在 Novius 物种对 Icerya 的适应中至关重要。
我们报告了迄今为止第一个 Novius 基因组。此外，我们还为 N. pumilus 提供了全面的转录组资源。本研究的结果可能有助于了解与化学感受、消化、解毒和免疫相关的基因进化与昆虫捕食者猎物适应的关系。这将为 Novius 在生物防治计划中的未来研究和利用提供参考。此外，了解猎物适应的可能分子机制也为 N. pumilus 和其他 Novius 的大规模繁殖提供了信息，这可能有利于害虫防治。
