定量蛋白质组学揭示三角鲂和团头鲂响应嗜水气单胞菌侵染机制变化

Differential Aeromonas hydrophila resistance mechanisms of Megalobrama terminalis and Megalobrama amblycephala revealed by quantification proteomics

细菌性败血症对鱼类危害严重,为探究鲂属鱼类不同抗性品种响应病原菌嗜水气单胞菌的抗性机制,以三角鲂(高抗)和团头鲂(易感)肝组织为材料,采用非标记定量蛋白质组学技术分析其在嗜水气单胞菌侵染胁迫后3、10和24h与对照组0h(未感染)肝组织蛋白质组的变化,对差异表达蛋白质进行质谱鉴定、相对定量和生物信息学分析。结果显示:三角鲂和团头鲂在嗜水气单胞菌侵染下,分别有46个和29个蛋白质在侵染后各时期的表达丰度相比对照都发生了显著变化。通过基因本体(gene ontology,GO)功能注释发现,相对于团头鲂,三角鲂中氧化还原蛋白质比例从7%增加到13%,且发现一类新的β-免疫球蛋白(β-globin)在各时期分别上调表达了1.64、3.44和1.93倍。生物信息学分析进一步表明,三角鲂在响应嗜水气单胞菌侵染过程中可能特异性地启动了包括戊糖磷酸途径、脂肪酸代谢、亮氨酸代谢途径和β-globin高表达的协同抗性机制,从而抵御病原菌入侵。该研究成果为后续深入揭示鱼病互作分子机制及鲂属鱼类抗病新品种选育提供了重要的前期理论研究基础。

Bacterial sepsis is a serious infection for fish.In the past years,the feeding cost of Megalobrama amblycephala had been seriously affected by bacterial sepsis.However,bacterial sepsis does not extensively occur during the feeding processes of Megalobrama terminalis.Therefore,M.terminalis which is highly resisted to bacterial sepsis is increasingly favored by farmers.To study the pathogen resistance mechanism of different varieties of Megalobrama fish in response to Aeromonas hydrophila,we used label-free based proteomics technology to study the proteome change of the livers of M.terminalis and M.amblycephalainfected with A.hydrophila at 0h,3h,10 hand 24h.After identification and relative quantification,49 and 29proteins changed at different post-infection time points in M.terminalis and M.amblycephala,respectively.The differentially expressed proteins were deeply analyzed by gene ontology annotation and bioinformatics,and we found that,by comparing with M.amblycephala,the percentage of differentially expressed redox proteins in M.terminalis increased from 7%to 13%,andβ-globin was up-regulated（1.66,3.44 and 1.93 times increased at 3time points）.Furthermore,we found that M.terminalis may specifically induce synergistic pathogen resistance mechanism including the regulation of pentose phosphate pathway,metabolism of fatty acids,leucine metabolism pathway and over-expression ofβ-globin to resist the invasion of pathogens.In summary,we studied four different stages of Megalobramaliver proteome expression after A.hydrophila infection,and found different pathogen resistance signal response pathway between two fish species,which indicates the resistance mechanism of different fish species after A.hydrophila infection.The result is of great benefit to further deeply reveal the molecular mechanisms of fish pathogen interactions and the breeding of pathogen-resistant Megalobramafish varieties.