不同抗流能力大黄鱼(Larimichthys crocea)肌肉转录组学差异分析

TRANSCRIPTOME ANALYSIS OF MUSCLE TISSUE OF LARIMICHTHYS CROCEA WITH DIFFERENT FLOW RESISTANCE

为揭示不同抗流能力的大黄鱼(Larimichthys crocea)肌肉基因表达水平的变化,筛选抗流相关基因,解析大黄鱼抗流性状形成的分子基础,收集福建福鼎沙埕湾主养区1000尾大黄鱼,在设计制作的抗流实验水槽中,以流速1.0m/s为筛选条件,将抗流时间>30 min的大黄鱼归为抗流组(HM组),抗流时间<5 min的大黄鱼归为非抗流组(SM组),对其肌肉进行转录组分析,并统计抗流分组后48 h内大黄鱼的累计死亡率。转录组结果显示,HM组与SM组文库共富集到1806个差异表达基因(DEGs),其中1090个上调,716个下调。GO功能注释发现显著富集的条目主要集中在肌肉收缩相关功能,KEGG富集分析发现上调的DEGs主要富集在心肌收缩、氧化磷酸化、黏着斑、ECM-受体相互作用、AGE-RAGE、MAPK、心肌细胞中的肾上腺素能等相关通路;下调的DEGs主要富集在真核生物核糖体的发生、蛋白酶体、内质网中的蛋白加工、RNA转运、泛素介导的蛋白水解信号通路等。此外,RT-qPCR结果表明,随机选取的DEGs与RNA-seq结果的表达趋势一致。48h的累计死亡率结果显示,SM组大黄鱼的死亡率显著高于HM组(P<0.05)。得出结论认为,抗流能力强的大黄鱼可能通过改变细胞内能量代谢及肌肉收缩的方式来提高机体应对水流的能力,且在较强水流刺激后能够获得较高的成活率,这为后续培育适宜深远海养殖的大黄鱼抗流新品种提供了理论依据。

To reveal the changes in the muscle gene expression levels of large yellow croaker(Larimichthys crocea)with different anti-flow abilities,screen anti-flow related genes,and analyze the molecular basis of the formation of anti-flow characteristics of large yellow croakers,1000 large yellow croakers were collected from the main breeding area of Shacheng Bay,Fuding,Fujian.In the anti-flow experiment,the flow rate was 1.0 m/s as the screening condition,and the anti-flow time was set at>30 min(HM group)and<5 min(SM group).The transcriptome was analyzed on its muscles,and the cumulative mortality of large yellow croakers within 48 h after the anti-flow group was calculated.A total of 1806 differentially expressed gene(DEGs)were screened from HM and SM group libraries,including 1090 up-regulated and 716 down-regulated genes.The GO functional annotation showed that significantly-enriched entries focused on muscle contraction-related functions.The up-regulated DEGs were significantly enriched in cardiac muscle,oxidative phosphorylation signal pathway,focal adhesion,ECM-receptor interaction,AGE-RAGE signaling pathway,MAPK signaling pathway,and adrenergic signaling in cardiomyocytes.The down-regulated DEGs were enriched in mainly ribosome biogenesis in eukaryotes,proteasome,protein processing in endoplasmic reticulum,RNA transport,and ubiquitin mediated proteolysis etc.Furthermore,the randomly selected DEGs for RT-PCR exhibited consistent results in the expression trend of the RNA-seq.The cumulative mortality within 48 h showed that the SM group mortality rate was significantly higher than that in the HM group(P<0.05).Therefore,the stronger flow-resistance ability may improve the ability of large yellow croaker body against turbulent flow by changing the way of intracellular energy metabolism and muscle contraction.This study provided a theoretical basis for future cultivation of new varieties of large yellow croaker for off-coast deep-water aquaculture.