Vuori Kristiina A M, Nikinmaa Mikko
Center of Excellence in Evoluationary Genetics and Physiology, Department of Biology, University of Turku, Finland.
Ambio. 2007 Apr;36(2-3):168-72. doi: 10.1579/0044-7447(2007)36[168:msibsa]2.0.co;2.
Baltic salmon suffer from maternally transmitted yolk-sac fry mortality syndrome--M74. The incidence of M74 varies considerably on a year to year basis. In the 1990s the mortalities were 50-80% but in 2003-2005, below 10%. Before death, M74-affected fry have several typical symptoms. M74-eggs are characterized by low thiamine and carotenoid content, and affected fry show signs of oxidative stress. Although M74 is associated with thiamine deficiency and the symptoms of the fry can be alleviated with thiamine, the underlying causes of the syndrome have remained a mystery. We have studied the symptoms of M74 at the molecular level by investigating the global gene expression patterns using cDNA microarray and have quantified the changes in transcriptional regulation in M74-affected and healthy yolk-sac fry. Our and previous results suggest that M74 in Baltic salmon yolk-sac fry results from oxidative stresses disturbing several different developmental molecular pathways. Because the M74 syndrome is of maternal origin, factors in the Baltic Sea during salmon feeding and migration, i.e., the chemical composition of food, may be decisive in the development of M74. The possible mechanisms by which oxidative stresses may develop in adult salmon are discussed in the review.
波罗的海鲑鱼患有母源性传播的卵黄囊仔鱼死亡综合征——M74。M74的发病率逐年变化很大。在20世纪90年代，死亡率为50%-80%，但在2003年至2005年，低于10%。在死亡前，受M74影响的仔鱼有几种典型症状。M74卵的特点是硫胺素和类胡萝卜素含量低，受影响的仔鱼表现出氧化应激迹象。尽管M74与硫胺素缺乏有关，且仔鱼的症状可用硫胺素缓解，但该综合征的根本原因仍是个谜。我们通过使用cDNA微阵列研究全局基因表达模式，在分子水平上研究了M74的症状，并量化了受M74影响的和健康的卵黄囊仔鱼转录调控的变化。我们的研究结果和之前的结果表明，波罗的海鲑鱼卵黄囊仔鱼的M74是由干扰几种不同发育分子途径的氧化应激引起的。由于M74综合征源于母体，鲑鱼摄食和洄游期间波罗的海的因素，即食物的化学成分，可能对M74的发展起决定性作用。综述中讨论了成年鲑鱼可能产生氧化应激的机制。
