牦牛卵泡发育过程中卵丘卵母细胞复合体的转录组分析

Analysis of transcriptome of cumulus-oocyte complexes during follicle development of the yak

为探讨牦牛有腔卵泡发育过程中卵丘卵母细胞复合体(Cumulus-oocyte complexes,COCs)mRNA转录组变化,对牦牛小(2~3mm)、中(4~5mm)、大有腔卵泡(6~8mm)中的COCs进行Illumina平台测序,筛选差异表达基因(Differentially expressed genes,DEGs),并进行GO分析和KEGG分析。结果表明,1)牦牛小、中、大3个阶段的卵泡COCs中共有17342个基因表达;2)小卵泡与中卵泡COCs之间有879个DEGs,其中,上调435个,下调444个;DEGs注释到106条GO条目,其中生物过程(BP)类别46条,细胞组成(CC)类别25条,分子功能(MF)类别35条,涉及254条KEGG通路。中卵泡与大卵泡COCs之间有1560个DEGs,其中,上调590个,下调970个;3)DEGs注释到114条GO条目,其中BP 55条、CC 26条和MF 33条,涉及276条KEGG通路,DEGs主要富集在神经活性配体-受体相互作用、细胞因子-细胞因子受体相互作用、细胞粘附分子、钙离子信号通路和cAMP信号通路等重要通路。综上,牦牛卵泡在不同发育阶段的DEGs、GO条目和KEGG pathway存在明显差异,为揭示牦牛卵泡发育分子调控机制,改善牦牛卵母细胞体外成熟技术提供了理论依据。

The objective of this study was to investigate dynamic change of transcriptome of cumulus-oocyte complexes(COCs)during antral follicle development of the yak(Bos grunniens).COCs obtained from small(2-3mm),medium(4-5mm)and large(6-8mm)antral follicles of the yak and RNA sequencing was performed by Illumina platform.The differentially expressed genes(DEGs)were identified,and GO analysis and KEGG annotation were conducted.The result showed that:1)A total of 17342 genes were expressed in COCs of small,medium and large follicles;2)A total of 879 DEGs were detected between small and medium COCs,of which 435genes were up-regulated and 444 genes were down-regulated.DEGs annotated 106 GO terms,including 46 terms in biological process(BP),25 terms in cellular component(CC)and 35 terms in molecular function(MF),involving 254 KEGG pathways.There were 1560DEGs between medium and large COCs,of which 590genes were up-regulated and 970 genes were downregulated.3)These DEGs were classified into 114 GO terms,including 55 terms in BP,16 terms in CC and 33 terms in MF,involving 276 KEGG pathways.The most important pathways were neuroactive ligand-receptor interaction,cytokine-cytokine receptor interaction,cell adhesion molecules,calcium signaling pathway,cAMP signaling pathway,etc.In conclusion,the results showed that there was a large difference in DEGs,GO terms and KEGG pathways at different stage of yak follicle development,which provided theoretical foundation for elucidating molecular mechanisms which control follicle development and for improving in vitro maturation of yak oocytes.