绵羊不同发育阶段背最长肌组织中可变剪接的鉴定与分析

Identification and Analysis of Alternative Splicing in Longissimus dorsi of Sheep at Different Development Stages

可变剪接(Alternative splicing,AS)是动植物体内蛋白质多样性和遗传多样性的重要调控机制。为鉴定和分析绵羊不同发育阶段背最长肌组织中可变剪接,对多浪绵羊妊娠90日龄胎儿(F90)、出生后30日龄羔羊(L30)和成年3岁羊(A3Y)的背最长肌组织进行转录组测序,利用rMATS软件鉴定样品中的可变剪接事件和差异剪接基因(Differential splicing gene,DSG),并对DSG进行GO和KEGG功能富集分析。结果表明,绵羊背最长肌组织在F90、L30和A3Y时期分别鉴定出13 923、11 959和12 164个可变剪接事件,其中外显子跳跃(Skipped exons,SE)的比例最高,约为70.69%,5'端可变剪接位点(Alternative 5'splice sites,A5SS)、3'端可变剪接位点(Alternative 3'splice sites,A3SS)、互斥外显子(Mutually exclusive exons,MXE)和内含子保留(Retained introns,RI)的比例分别约为7.28%、11.18%、5.96%和4.84%。在F90_vs_L30、F90_vs_A3Y和L30_vs_A3Y比较组中分别鉴定到2 545、2 689和1 701个显著的差异剪接基因(P<0.05)。GO和KEGG功能富集分析显示,差异剪接基因显著富集到横纹肌发育、肌肉结构发育、肌细胞分化、肌膜、胰岛素信号通路、Wnt信号通路、MAPK信号通路等与肌肉发育密切相关的通路上。上述结果表明可变剪接在背最长肌发育中发挥重要作用。

The alternative splicing(AS)is an important regulatory mechanism of protein diversity and genetic diversity in animals and plants.The objective of this study was to identify and analyze alternative splicing in the longissimus dorsi of sheep at different developmental stages.The transcriptomic profiling of the longissimus dorsi of 90-day-old fetus(F90),30-day-old lamb(L30)and adult 3-year-old sheep(A3Y)were sequenced,and the alternative splicing event(AS)and differential splicing gene(DSG)were identified using rMATS software.The GO function enrichment and KEGG pathway analysis were performed for DSG.The results showed that 13 923,11 959 and 12 164 alternative splicing events were identified in genome of longissimus dorsi tissues in the F90,L30 and A3Y,respectively,and the proportion of skipped exons(SE)was the highest,about 70.69%of the total number of AS.The proportion of 5'splice sites(A5SS),3'splice sites(A3SS),mutually exclusive exons(MXE)and retained introns(RI)was about 7.28%,11.18%,5.96%,and 4.84%,respectively.2 545,2 689,and 1 701 significant differentially spliced genes(P<0.05)were identified in the F90_vs_L30,F90_vs_A3Y and L30_vs_A3Y groups,respectively(P<0.05).The GO and KEGG analysis showed that differentially spliced genes were significantly enriched in striated muscle development,muscle structure development,myocyte differentiation,sarcolemma,insulin signaling pathway,Wnt signaling pathway,MAPK signaling pathway and other pathways closely related to muscle development.These results suggest that alternative splicing plays an important role in the development of the longissimus dorsi.