低温胁迫下鱼类鳃中RPL11/MDM2/P53信号通路相关基因及蛋白表达差异分析

Expression analysis of RPL11/MDM2/P53 pathway related gene and protein in gills of fish exposed to cold stress

为了研究RPL11/MDM2/P53信号通路在鱼类低温胁迫中所起的作用,分别利用mRNA和蛋白表达水平定量技术,对罗非鱼Oreochromis niloticus和斑马鱼Danio rerio两种抗寒能力不同的鱼类鳃RPL11/MDM2/P53信号通路相关因子在低温胁迫下的表达情况进行分析。结果表明:在相同低温胁迫下,罗非鱼鳃中RPL11和P53蛋白表现出随着低温胁迫时间延长而增加的趋势,但斑马鱼鳃中P53蛋白开始增加的时间点晚于罗非鱼;罗非鱼鳃中mdm2转录表达量在8℃、6 h后显著升高(P<0.05),表明mdm2表达量升高可能活化P53;8℃、6 h后P53下游靶基因bad和p21在罗非鱼鳃中出现表达量升高的情况,这与罗非鱼中6 h时P53蛋白表达量升高是一致的,但在斑马鱼中p21基因表达量变化不大。研究表明,低温能诱导罗非鱼中与凋亡相关的RPL11/MDM2/P53通路中相关蛋白的变化,并且这种表达变化模式与耐低温能力较强的斑马鱼不同,这种物种差异性的基因表达模式可能是不同鱼类低温耐受能力差异的原因之一。

The differential expressions of several factors(related gene and protein)involved in RPL11/MDM2/P53 signaling pathway were investigated in gills of 6 month old Nile tilapia Oreochromis niloticus and zebrafish Danio rerio exposed to 8℃from 28℃in culture to evaluate the role of RPL11/MDM2/P53 under cold stress in cold tolerance in the two species fishes.Results showed that RPL11 and P53 protein expression was elevated in gill of tilapia with increase in cold stress period,whereas the zebrafish began to accumulate P53 in gills later than the tilapia did.The mdm2 mRNA expression level in tilapia gill was significantly increased after 6 h at 8℃(P<0.05),which may result in P53 activation.Expression level of P53 downstream target gene(bad and p21)was shown to be increased at 8℃in 6 h after tilapia,with change in accordance with the change in P53 expression level.However,bad and p21 expression level of tilapia was different from zebrafish.The findings indicated that cold stress induced protein involved in apoptosis and related to RPL11/MDM2/P53 pathway expression change in tilapia,which was different from zebrafish which had stronger cold tolerance than tilapia.The species specific gene expression pattern may be involved in different cold tolerance abilities between tilapia and zebrafish.