榛子胚珠不同发育阶段circRNA的分析与鉴定

Analysis and Identification of circ RNAs of Hazel Ovule at Different Developmental Stages

在榛子胚珠不同发育时期筛选差异表达的circ RNA,进一步鉴定其差异表达的靶m RNA,以期明确circRNA在胚珠中的表达特征及其对胚珠发育的调控作用。在榛子胚珠形成期(Ov1)、早期生长期(Ov2)、快速生长期(Ov3)和成熟期(Ov4)进行胚珠样品采集和Illumina高通量测序,结合已有的m RNA测序分析结果,鉴定参与胚珠发育的差异表达circRNA(DEcircRNA)及其靶差异表达mRNA(DEmRNA)。共鉴定到7122条circRNA,59.54%的circRNA来自外显子区域。在成对比较Ov1-vs-Ov2、Ov1-vs-Ov3、Ov1-vs-Ov4、Ov2-vs-Ov3、Ov2-vs-Ov4和Ov3-vs-Ov4中,分别鉴定到123、162、187、85、105和21条DEcircRNA;DEcircRNA的表达有明显的发育时期特异性;有199条DEcircRNA的靶m RNA也发生差异表达,两者表达变化高度同步。GO(GeneOntology)分类结果表明DEcircRNA参与胚珠发育过程中代谢的调控。随机选择了4个差异表达circRNA及靶m RNA,用qRT-PCR分析其在4个胚珠发育阶段表达量的变化,证实qRT-PCR与Illumina高通量测序结果相一致。

The differentially expressed circRNA(DEcircRNA)of hazel ovule were screened at different developmental stages,and their target differentially expressed mRNA(DEmRNA)was further identified to clarify the regulatory effect of circRNAs on ovule development.Samples were collected from ovule formation stage(Ov1),early growth stage(Ov2),rapid growth stage(Ov3)and maturation stage(Ov4)of hazel.The DEcircRNA involved in ovule development was identified based on the available results of mRNA sequencing analysis at four developmental stages.A total of 7122 circRNAs were identified,and 59.54%of them came from exon region.In pairwise comparisons of Ov1-vs-Ov2,Ov1-vs-Ov3,Ov1-vs-Ov4,Ov2-vs-Ov3,Ov2-vs-Ov4 and Ov3-vs-Ov4,123,162,187,85,105 and 21 DEcirc RNAs were identified respectively.The expression pattern of DEcirc RNAs was developmental stage specific.Correlation analysis showed that 199 target mRNAs of DEcircRNA were also differentially expressed.The expression changes of DEcircRNA and their responding DEmRNA were highly synchronized.The results of GO(Gene Ontology)classification indicated that DEcircRNAs were involved in the regulation of metabolism during ovule development.Four DEcircRNAs and their target differentially expressed mRNAs at four ovule development stages were randomly selected and subjected to qRT-PCR analysis,and their expression levels changes were consistent with the results of high-throughput sequencing of microRNAs.