光强对欧洲舌齿鲈稚鱼眼组织基因表达的影响

Effect of light intensity on gene expression in the eyes of Dicentrarchus labrax juveniles

大多数海水鱼类靠视觉器官识别并捕捉饵料,光强对其视觉器官基因表达影响的研究较少。为探究光照强度对鱼类眼内基因表达的影响,本实验以孵化后30 d的欧洲舌齿鲈为研究对象,在白光2.0 W/m^(2)(W 2.0)、1.0 W/m^(2)(W 1.0)和0.3 W/m^(2)(W 0.3)条件下对其进行了为期66 d的养殖实验。实验结束后,首先比较三组稚鱼的体长、湿重和存活率,结果发现,W 2.0组饲养的稚鱼体长和湿重显著低于W 1.0和W 0.3组稚鱼(P<0.05),但三组之间的存活率无显著性差异(P>0.05)。然后,我们构建了W 2.0和W 0.3组两组稚鱼眼组织的转录组文库并进行高通量测序,结果共获得差异表达基因368个,与W 0.3组相比,W 2.0组中234个基因上调表达,134个基因下调表达。最后对筛选得到的晶状体纤维主要固有蛋白(lens fiber major intrinsic protein,MIP),视黄醇结合蛋白(retinol-binding protein,RBP),维生素A脱氢异构酶(retinoid isomerohydrolase,RPE65),热休克同源70(heat shock cognate 70,HSC70),伸长因子1-α(elongation factor 1-alpha,EF1A)和葡萄糖-6-磷酸异构酶(glucose-6-phosphate isomerase,GPI)6个差异表达基因进行qPCR验证,结果与转录组数据一致,且它们可能在稚鱼响应光照强度的过程中起着重要作用。以上结果说明光照强度可以影响鱼类眼内基因的表达,将为研究光照强度对鱼类视觉的影响机制提供基础数据,同时也对欧洲舌齿鲈稚鱼的健康养殖具有一定的参考价值。

Most marine fishes rely on their sensory organs to recognize and catch food,but there are few studies on the effect of light intensity on gene expression in the visual organ.In this study,to explore the effect of light intensity on gene expression in the eyes of fish,juvenile Dicentrarchus labrax at 30 days post hatching were used as research subjects,reared under white light at 2.0 W/m^(2)(W 2.0),1.0 W/m^(2)(W 1.0),and 0.3 W/m^(2)(W 0.3)for 66 days.At the end of the experiment,the body length,wet weight,and survival rate of the three groups were compared.The body length and wet weight of the W 2.0 group were significantly lower than those of the W 1.0 and W 0.3 groups(P<0.05),but there was no significant difference in the survival rate among the three groups(P>0.05).Then,the transcriptome libraries of juvenile eyes of W 2.0 and W 0.3 groups were constructed and subjected to high-throughput sequencing.A total of 368 differentially expressed genes were obtained.Compared with the W 0.3 group,234 genes were upregulated,and 134 genes were downregulated in the W 2.0 group.Finally,the expression of six differently expressed genes,including lens fiber member intrinsic protein,retina binding protein,retina isomerohydrolase,heat shock conjugate 70,elongation factor 1-alpha,and glucose-6-phosphate isomerase,were validated by qPCR(Quantitative Real-time PCR).The results were consistent with the transcriptomic data,and those genes may play a key role in the juvenile response to light intensity.These results indicate that light intensity can affect gene expression in fish eyes,and this study provides basic data on the mechanism by which light intensity modifies fish vision.It also serves as a reference for the healthy cultivation of Dicentrarchus labrax juveniles.