Responses to ectoparasite salmon louse (Lepeophtheirus salmonis) in spleen of Atlantic salmon

Gene expression profiling revealed rapid activation of immunity, both local and systemic, which however did not provide protection of fish against the parasite. Major changes of transcriptome responses wwere observed between days 5 and 10 Atlantic salmon was challenged with L. salmonis at the copepod stage. Skin, spleen, and head kidney were sampled from challenged and control fish at 1, 3, 5 dpi (corresponding to the copepod stage); 10 and 15 dpi (chalimus stage). A total of forty samples of spleen and skin form infected salmon (4 individuals from the 5 time points) were used for microarray analyses.. Test samples were labeled with Cy5 and hybridized to pooled control samples labeled with Cy3 from the same time-points. Competitive hybridization to the arrays was followed by washing, scanning, image analysis, and data analysis. Selected genes were analyzed with RT-qPCR.基因表达谱分析（Gene expression profiling）显示，大西洋鲑（Atlantic salmon）在桡足幼体阶段（copepod stage）感染鲑疮痂鱼虱（L. salmonis）后，其局部与全身免疫均被快速激活，但该免疫应答并未使鱼类获得针对该寄生虫的保护力。转录组应答的显著变化出现在感染后第5天至第10天期间。随后，研究人员分别于感染后天数（days post infection, dpi）1、3、5（对应桡足幼体阶段）以及10、15（对应chalimus幼体阶段），从感染组与对照组鲑鱼的皮肤、脾脏和头肾中采集样本。本研究共使用40份来自感染鲑鱼的脾脏与皮肤样本（5个时间点各4个个体）开展基因芯片分析（microarray analyses）：实验样本以Cy5荧光标记，并与同时间点经Cy3荧光标记的混合对照组样本进行杂交。阵列竞争性杂交完成后，依次进行洗涤、扫描、图像分析与数据分析。最后，选取部分目标基因通过实时定量荧光PCR（Reverse transcription quantitative real-time polymerase chain reaction, RT-qPCR）进行验证分析。