栖息于青藏高原不同海拔环境的两种草原毛虫miRNA转录组的比较分析

Comparative analysis of the micro RNA transcriptomes between two Gynaephora species(Lepidoptera: Lymantriinae) inhabiting different high altitudes of the Tibetan Plateau

有关动物适应异质性海拔环境的研究,已在表型、解剖学、生理学、基因组学和转录组学等方面广泛开展,但是很少关注小RNA(micro RNAs或miRNAs)的生态适应性功能.草原毛虫是青藏高原高寒草地的重要害虫,并对不同海拔环境产生了良好的适应性.为此,本研究以两种栖息于青藏高原不同海拔环境的黄斑草原毛虫和门源草原毛虫为研究对象,基于Illumina Hi Seq技术对这两种草原毛虫的miRNA转录组进行了高通量测序.结果表明,两种草原毛虫中共鉴定到109个成熟miRNAs,其中47个为保守miRNAs.在所有miRNAs种,共有9个miRNAs的表达水平在两种草原毛虫间存在显著差异性.对这9个差异性表达的miRNAs采用实时荧光定量PCR进行验证,发现8个基因的表达水平与高通量测序结果完全一致.功能分析表明,差异性表达的miRNAs共预测到93个靶基因.这些靶基因主要富集到脂、核酸和维生素等代谢或衰老相关的GO条目,并与代谢、抗寒和低氧等KEGG通路相关(如AMPK信号通路、Wnt信号通路和m TOR信号通路).这些研究表明,miRNAs在草原毛虫对异质性海拔环境的适应性进化过程中具有重要作用.该研究加深了对青藏高原特有昆虫适应高海拔环境的遗传基础的理解.

Divergent-altitude adaptation in animals has been extensively investigated at various levels,such as morphology,anatomy,physiology,genomics and transcriptomics,but few studies focused on the roles of micro RNA（miRNA）in ecological adaptation.Grassland caterpillars（Gynaephora）endemic to the Tibet Plateau（TP）are important insect pests of alpine grasslands and have well adapted to different altitude environments.In this study,we used Illumina Hi Seq technique to sequence miRNA transcriptomes of Gynaephora menyuanensis and Gynaephora alpherakii.These two Gynaephora species are locally distributed in different altitudes.A total of 109 mature miRNAs were identified in the two species,of which 47 conserved miRNAs were determined.Nine miRNAs with significantly differentiated expression were presented between the two Gynaephora species,among which eight miRNAs showed the same expression patterns between the Illumina Hi Seq and quantitative real-time PCR results.Functional analyses for 93 target genes of differentially expressed miRNAs revealed that these targets were enriched to GO terms involving metabolism of lipid,nucleic acid,vitamin and aging,and several KEGG associated with metabolic,cold-and hypoxia-related pathways,such as the AMPK signaling pathway,the Wnt signaling pathway and the m TOR signaling pathway.These results indicated the important roles of miRNAs in the adaptive evolution of Gynaephora species to different altitudes and provide insights into the genetic basis of high-altitude adaptation of insects endemic to the TP.