不同年龄高体鰤精巢转录组分析OACHSSCD

[Objective]This study aims to investigate the molecular mechanisms regulating testicular development in greater amberjack(Seriola dumerili)at different age stages under artificial aquaculture conditions.[Methods]Histological observation,transcriptome sequencing analysis,gene functional annotation,and screening and identification of differentially expressed genes(DEGs)were performed on the testis of 1-year-old and 2-year-old greater amberjack.The expression levels of genes related to testicular development were detected using real-time quantitative PCR(qPCR).[Results]Histological analysis showed that the testis of 1-year-old fish were at Stage I,while those of 2-year-old fish were at Stage IV.Transcriptome sequencing of testis from 1 and 2 age groups yielded 263 476 570 clean reads,corresponding to 21 258 annotated genes,among which 1 108 were identified as differentially expressed genes(DEGs).Functional enrichment analysis revealed that numerous DEGs were involved in reproduction-related metabolic pathways,including steroid hormone biosynthesis,GnRH signaling pathway,TGF-beta signaling pathway,and Wnt signaling pathway.Both transcriptome data and qPCR results indicated that,compared with 1-year-old fish,11 genes,namely spata18,spata6,sycp3,smc3,sycp2,mns1,spag17,rsph1,spef2,spa17,and spaca6 were significantly up-regulated in the testis of 2-year-old fish,while 5 genes,namely gsdf,gdf3,and foxl2,cyp19a1a,and bmp8 were significantly down-regulated.[Conclusion]Through transcriptome sequencing analysis of testis from 1-year-old and 2-year-old greater amberjack,this study identified age-related differentially expressed genes and meta-bolic pathways involved in testicular development,preliminarily revealing regulation mechanisms of testis development in S.dumerili at the molecular level.