【摘要】 为研究吉富罗非鱼感染无乳链球菌后肝脏组织多肽表达变化,采用串联飞行时间质谱仪(MALDI-TOF/TOF)扫描了吉富罗非鱼感染无乳链球菌24 h后与未感染的罗非鱼肝脏组织的多肽质谱峰值差异,并对表达差异的多肽峰值进行蛋白质质谱鉴定和功能分类。结果显示:对照组检测到信噪比(s/n)大于50的质谱峰为44个,试验组为52个,发现6个质谱峰(m/z 1 082,1 161,1 196,1 459,1 740,1 877)在感染24 h后与未感染鱼之间的表达差异明显,其中质荷比(m/z)1 196在试验组表达下降,而质荷比(m/z)1 161和1 459则是上升。共鉴定得到19种多肽,其中14个表达上调,4个下调,1个无明显变化。经生物信息学分析,鉴定得到的多肽分别参与了三羧酸循环、DNA拼接和细胞防御3条信号调控通路。选择其中的ATP合成酶6(ATP6)和beta-羟基丁酸脱氢酶(Bhd1)基因进行qRT-PCR验证,发现ATP6基因在感染24 h后的转录水平显著升高,而Bhd1基因的转录水平则是显著降低,与多肽组相对定量的结果相符。研究结果为无乳链球菌病的早期诊断提供了新的参考依据。更多还原

【Abstract】 The polypeptide expression on GIFT tilapia liver was studied after infecting Streptococcus agalactiae.Matrix-assisted Laser Desorption Ionization Time of Flight( MALDI-TOF) was employed to analyze the polypeptide,and they were identified by mass spectrometry. The results indicated that there were 44 and 52 polypeptide between control group and experimental group,which Signal/Noise( s/n) was more than 50. We discovered 6 peaks( m/z1 082,1 161,1 196,1 459,1 740,1 877) was obvious difference in two groups( P < 0. 01). The 1 196( m/z) peptide decreased,but the 1 161 and 1 459( m/z) peptide increased in experimental group. All the mass spectrums were corresponding to 19 peptides,and 14 shows a up-regulated expression,4 shows down-regulated expression,and 1 shows no obvious change. The results of bioinformatical analysis indicated that all the peptides were involved in three regulation pathways including TCA cycle,DNA splice and cell defensive signaling pathway. Real-time PCR was utilized to analysis the mRNA variation of ATP synthase 6( ATP6) gene and D-beta-hydroxybutyrate dehydrogenase( Bhd1) gene. The results confirmed the positive correlation of gene expression and protein expression. The results of peptidome analysis provided a new approach to diagnose the Streptococcus agalactiae disease.更多还原