›› 2018, Vol. 61 ›› Issue (8): 905-913.doi: 10.16380/j.kcxb.2018.08.003

• 研究论文 • 上一篇    下一篇

亮斑扁角水虻脂肪酸去饱和酶基因的鉴定及其在双翅目中的进化格局

刘贵芬1,2, 房刚奇2, 詹帅2,*, 黄勇平2   

  1. (1. 上海大学生命科学学院, 上海 200444; 2. 中国科学院上海植物生理生态研究所, 中科院昆虫发育与进化重点实验室, 上海 200032)
  • 出版日期:2018-08-20 发布日期:2018-08-20

Identification of fatty acid desaturase genes in Hemetia illucens (Diptera: Stratiomyidae) and their evolutionary pattern in Diptera

LIU Gui-Fen1,2, FANG Gang-Qi2, ZHAN Shuai2,*, HUANG Yong-Ping2   

  1.  (1. School of Life Sciences, Shanghai University, Shanghai 200444, China; 2. CAS Key Laboratory of Insect Developmental and Evolutionary Biology, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China)
  • Online:2018-08-20 Published:2018-08-20

摘要: 【目的】在全基因组水平鉴定亮斑扁角水虻Hemetia illucens脂肪酸去饱和酶(fatty acid deaturase, FAD)基因,分析其时空表达格局,研究代表性双翅目昆虫FAD家族基因的系统发育和进化关系。【方法】以FlyBase数据库中的黑腹果蝇Drosophila melanogaster FAD氨基酸序列作为种子序列,通过本地Blastp的方法在全基因组范围搜索和鉴定亮斑扁角水虻和其他代表性双翅目昆虫的FAD家族基因;采用MEGA7.0软件通过邻接法(neighbor-joining method, NJ)推断该家族基因在双翅目昆虫中的系统发育关系,并构建了双翅目代表性昆虫FAD家族的系统发育进化树;基于亮斑扁角水虻转录组数据分析亮斑扁角水虻FAD基因在其代表性组织和生长发育时期中的表达格局并且利用RT-PCR进一步验证。【结果】本研究在亮斑扁角水虻全基因组中共鉴定到13个FAD基因,并预测了这些基因的部分特征。系统发育分析结果表明,编码亮斑扁角水虻FAD家族的基因某些成员发生了基因复制事件,例如HillFAD-10和HillFAD-12以及HillFAD-9和HillFAD-11基因;与此相反的是,亮斑扁角水虻某些FAD基因在双翅目昆虫中呈现出相似的进化模式,例如HillFAD-5HillFAD-6基因,说明这些基因在双翅目昆虫进化中相对比较保守并且可能发挥重要作用。转录组数据分析及RT-PCR结果显示,亮斑扁角水虻FAD家族基因在其变态发育期间呈现不同的表达模式,其中,HillFAD-2和HillFAD-6在胚胎期、幼虫前期、蛹期和成虫期均有表达,HillFAD-3主要集中于胚胎后期至4龄幼虫期间表达;与此相反,HillFAD-4在整个发育阶段均呈现出低表达状态,说明FAD家族基因可能在亮斑扁角水虻变态发育过程中发挥不同作用。【结论】本研究结果不仅在全基因组范围鉴定了亮斑扁角水虻脂肪酸去饱和酶基因,而且预测了FAD基因家族在双翅目中的进化格局,有助于更好地了解FAD基因在物种生态适应性中发挥的作用;同时,我们鉴定的FAD基因在亮斑扁角水虻中的表达格局也提示了FAD基因在亮斑扁角水虻脂肪代谢过程中发挥重要作用。

关键词: 亮斑扁角水虻, 脂肪酸去饱和酶, 双翅目, 系统发育分析, 进化, 时空表达

Abstract: 【Aim】To identify fatty acid desaturase (FAD) genes in the whole genome of Hermetia illucens, and to investigate their spatiotemporal expression patterns and evolutionary pattern in representative dipteran insects. 【Methods】 The amino acid sequences of FAD genes of Drosophila melanogaster were downloaded from FlyBases and used as seed sequences to search for FAD genes in H. illucens and several other representative species of Diptera by the local Blastp program across the whole genome. The phylogenetic tree of the FAD genes across several dipteran species was constructed by a neighbor-joining method (NJ) with MEGA7. 0. The expression patterns of FAD genes in representative tissues and developmental stages were determined based on the transcriptome data of H. illucens and were further verified using RT-PCR. 【Results】 In this study, a total of 13 FAD genes in the whole genome of H. illucens were identified and annotated with general characteristics. The phylogenetic analysis revealed that gene duplication occurs in partial H. illucens FAD genes, such as HillFAD-10 and HillFAD-12, and HillFAD-9 and HillFAD-11. In contrast, we also found that partial FAD genes, such as HillFAD-5 and HillFAD-6, present a consistent evolutionary pattern in dipteran species, suggesting that they are relatively conserved and may play general roles in dipteran species. Transcriptome data analyses and RT-PCR results revealed that most FAD genes showed different expression patterns during the growth and development of H. illucens, e.g., HillFAD-2 and HillFAD-6 were expressed in embryo, larval, pupal and adult stages, HillFAD-3 were mainly expressed during the late embryo and the 4th instar larval stage while HillFAD-4 showed low expression levels in the whole developmental satge, suggesting that the FAD genes may play distinctive roles in the metamorphosis development process of H. illuences. 【Conclusion】 Our study not only identified the whole set of FAD genes in the whole genome of H. illucens, but also reconstructed their evolutionary pattern across dipteran species, enabling us to better understand the role of FAD in the ecological adaptation in Diptera. The expression patterns of FAD genes uncovered in this study also provide preliminary insights into the lipid metabolism in this important resource insect species.

Key words: Hemetia illucens, fatty acid desaturase, Diptera, phylogenetic analysis, evolution, spatiotemporal expression