Transcriptomic profiling of egg quality in seabass (Dicentrarchus labrax)

The aim of the project was to identify differently expressed genes in eggs of European seabass (Dicentrarchus labrax) characterized by different quality. In this way it was expected to identify genes possibly being a molecular indicator of egg quality in this species, which was never studied to date. For the study microarray analysis of over 26 thousand genes in 16 egg batches was performed. Additionally, for each egg batch biological quality was determined, what allowed to compare the gene expression profile with overall egg quality (divided into two groups representing ‘high’ and ‘low’ egg quality). The analysis allowed to identify 39 differently expressed genes between the two groups representing ‘high’ and ‘low’ egg quality. From those genes, expression level of 7 were verified by real-time qPCR which confirmed significant difference in expression in 5 of them. Sixteen egg batches of European seabass was collected and divided into two portion. One portion was deep frozen and later used for the molecular analysis (microarray and real-time qPCR). Second portion was fertilized and incubated in order to verify the biological quality of the eggs. In this way two separate experimental groups, representing ‘low’ and ‘high’ egg quality, were created.

本研究旨在筛选不同品质欧洲海鲈（Dicentrarchus labrax）鱼卵中的差异表达基因，以期找到可作为该物种鱼卵品质分子标志物的候选基因，此类研究迄今尚未见报道。本研究共采集16批欧洲海鲈鱼卵，均分为两份：一份经深冻保存，后续用于分子生物学分析（基因芯片与实时荧光定量PCR）；另一份进行受精与孵化实验，以测定鱼卵的生物学品质，由此构建出分别代表‘低品质’与‘高品质’的两个独立实验组。随后，本研究对16批鱼卵中的逾26000个基因开展基因芯片（microarray）分析；同时针对每批鱼卵的生物学品质测定结果，将鱼卵划分为‘高品质’与‘低品质’两组，并将基因表达谱与整体鱼卵品质进行关联分析。通过上述分析，两组间共筛选得到39个差异表达基因。其中7个基因的表达水平经实时荧光定量PCR（real-time qPCR）验证，最终确认其中5个基因的表达量存在显著差异。