The Atlantic salmon has been studied extensively, particularly as a model for understanding the genetic and environmental contributions to the evolution and development of life history traits. Expression pattern analysis in situ, however, is mostly lacking in salmon. We examine the embryonic developmental expression of six6, a candidate gene previously identified to be associated with spawning ecotypes and age at sexual maturity, in Atlantic salmon. Six6 is a member of the sine oculis homeobox family of transcription factors and is known to regulate eye and brain development in other vertebrates. We assay the expression of this gene in embryonic Atlantic salmon Salmo salar by whole-mount in situ hybridization. In line with earlier studies in other vertebrate species, we find conserved expression in the developing brain and sensory organs, including optic and olfactory primordia. However, we also find previously unreported domains of expression that suggest additional roles in axial and appendicular development, cardiovascular, intestinal, and sensory organogenesis. Each of these systems are important in the sensory ecology of Atlantic salmon, suggesting it is plausible that six6 may have pleiotropic roles in this complex phenotype.

大西洋鲑鱼已被广泛研究，特别是作为了解遗传和环境对生活史特征进化和发展的贡献的模型。然而，在鲑鱼中大多缺乏原位表达模式分析。我们检查了66的胚胎发育表达，这是一种先前确定与大西洋鲑鱼产卵生态型和性成熟年龄相关的候选基因。Six6是转录因子的正弦同源盒家族的成员，已知可调节其他脊椎动物的眼睛和大脑发育。我们通过整体原位检测该基因在胚胎大西洋鲑鱼Salmo salar 中的表达杂交。与其他脊椎动物物种的早期研究一致，我们发现发育中的大脑和感觉器官（包括视原基和嗅觉原基）的表达保守。然而，我们还发现了以前未报告的表达域，这些域表明在轴向和阑尾发育、心血管、肠道和感觉器官发生中的其他作用。这些系统中的每一个在大西洋鲑鱼的感官生态学中都很重要，这表明66可能在这种复杂的表型中具有多效性。