为探讨盐度变化对大黄鱼(Larimichthys crocea)肝脏基因转录表达的影响,将体质量为(59.68±1.32)g的大黄鱼分别在盐度25(对照组)、盐度36(高盐组)、盐度10(低盐组)的水体中暴露24 h,采用Illumina Hiseq 2500对肝脏样本进行转录组测序.结果显示,从高盐vs.对照组(H vs.C)、低盐vs.对照组(L vs.C)和高盐vs.低盐(H vs.L)中分别筛选出71个、180个和438个差异基因(DEGs).GO(Gene Ontology)和KEGG(Kyoto Encyclopedia of Genes and Genomes)分析发现,H vs.C中的DEGs显著富集在三羧酸循环、MAPK信号通路、内质网蛋白加工和Toll样受体信号通路等;L vs.C中的DEGs显著富集在FoxO信号通路、戊糖磷酸途径、mTOR信号通路、RNA降解、P53信号通路和内质网蛋白加工等,表明大黄鱼对高盐和低盐胁迫的响应均涉及到糖类代谢、内质网应激、细胞凋亡和自噬等生理功能.Hvs.L中的DEGs显著富集在内质网蛋白加工、FoxO信号通路、甘油脂代谢、糖酵解/糖异生、吞噬体和P53信号通路等,表明大黄鱼在高盐和低盐适应过程中,内质网应激、脂类代谢、糖类代谢、细胞凋亡和自噬等生理功能存在差异.研究结果可为深入研究鱼类对盐度胁迫的响应机制奠定基础.
Comparative transcriptome analysis of the liver in Larimichthys crocea under different salinity stresses
Large yellow croaker Larimichthys crocea is an important marine fish species,the annual yield of which is the highest among marine cage-farmed fish species in China.To improve the economic benefits of aquaculture,high stocking density of this species is conducted in practice,which often leads to white spot disease outbreaks.The reduction of salinity can promote fish growth and reduce the risk of Cryptocaryon irritans infection.However,little information is available on the molecular mechanism of positive effects of reducing salinity on fish.The purpose is to investigate the effects of salinity on gene transcriptome in the liver of L.crocea.Fish with an average weight of(59.68±1.32)g were transferred from salinity 25 to salinity 36 or salinity 10.Three groups were set:control group(C group),high-salinity group(H group)and low-salinity group(L group),each group with three replicates.After exposure for 24 h,liver was sampled for the transcriptome sequencing.The results showed that 71,180 and 438 differentially expressed genes(DEGs)were obtained in high-salinity group vs.control group(H vs.C),low-salinity group vs.control group(L vs.C),and high-salinity group vs.low-salinity group(H vs.L),respectively.Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway analysis showed that DEGs in H vs.C were significantly enriched in citrate cycle,protein processing in endoplasmic reticulum,mitogen-activated protein kinase(MAPK)signaling pathway and Toll-like receptor signaling pathway.Citrate cycle is an important aerobic metabolic pathway,which can efficiently provide energy.Protein processing in endoplasmic reticulum can repair damaged cells and maintain correct protein folding.MAPK and Toll-like receptor signaling pathway can stimulate non-specific immune responses by activating multiple immune cells.Thus,fish adapted to high-salinity stress by regulating energy metabolism,non-specific immunity and endoplasmic reticulum stress.DEGs in L vs.C were significantly enriched in forkhead box O(FoxO)signaling pathway,pentose phosphate pathway,mammalian target of rapamycin(mTOR)signaling pathway,RNA degradation,P53 signaling pathway and protein processing in endoplasmic reticulu.FoxO is an important transcription factor of autophagy,which can degrade oxidative damaged cells(organelles)into small molecule substances,not only reducing oxidative stress,but also providing raw materials for cell reconstruction and energy metabolism.mTOR signaling pathway can maintain cellular homeostasis by regulating autophagy and oxidative reactions.P53 signaling pathway can repair DNA damage by participating in chromatin remodeling and base excision,and also has the function of regulating apoptosis.Thus,fish adapted to low-salinity stress involved carbohydrate metabolism,endoplasmic reticulum stress,apoptosis,autophagy,and so on.DEGs in H vs.L were significantly enriched in protein processing in endoplasmic reticulum,FoxO signaling pathway,glycerolipid metabolism,glycolysis/gluconeogenesis,phagosome and P53 signaling pathway,suggesting that there were differences in endoplasmic reticulum stress,lipid metabolism,carbohydrate metabolism,apoptosis and autophagy during fish responding to high-salinity and low-salinity stresses.In conclusion,these findings provide research basis for further study on the adaptive mechanism of fish under salinity stress,and also provide basic data for salinity regulation or water selection in L.crocoa croaker aquaculture.
万方数据
维普
