Data from: Near absence of differential gene expression in the retina of rainbow trout after exposure to a magnetic pulse: implications for magnetoreception

The ability to perceive Earth’s magnetic field, or magnetoreception, exists in numerous animals. Although the mechanism underlying magnetoreception has not been clearly established in any species, in salmonid fish it is hypothesized to occur by means of crystals of magnetite associated with nervous tissue such as the brain, olfactory organ, or retina. In this study, rainbow trout (Oncorhynchus mykiss) were exposed to a brief magnetic pulse known to disrupt magnetic orientation behavior in several animals. Changes in gene expression induced by the pulse were then examined in the retina. Analyses indicated that the pulse elicited differential expression of only a single gene, gamma-crystallin M3-like (crygm3). The near-absence of an effect of the magnetic pulse on gene expression in the retina stands in sharp contrast to a recent study in which 181 genes were differentially expressed in brain tissue of O. mykiss after exposure to the same pulse. Overall, our results suggest either that magnetite-based magnetoreceptors in trout are not located in the retina, or else that they are unaffected by magnetic pulses that can disrupt magnetic orientation behavior in animals.能够感知地球磁场的能力（磁感应，magnetoreception）广泛存在于众多动物类群中。尽管目前尚未在任何物种中明确阐明磁感应的作用机制，但学界假说认为，在鲑科鱼类中，磁感应过程可能通过与脑组织、嗅觉器官或视网膜等神经组织相关联的磁铁矿晶体实现。本研究将虹鳟（Oncorhynchus mykiss）暴露于已知可破坏多种动物磁定向行为的短时磁脉冲中，随后检测其视网膜内由该脉冲诱导的基因表达变化。分析结果显示，该脉冲仅诱导了单个基因的差异表达，即gamma-晶状体蛋白M3样基因（crygm3）。磁脉冲对视网膜基因表达几乎无影响的结果，与近期一项研究形成鲜明对比：该研究发现，虹鳟脑组织在暴露于相同磁脉冲后，共有181个基因出现差异表达。综上，本研究结果提示两种可能性：要么虹鳟体内基于磁铁矿的磁感应受体并不位于视网膜中，要么这类受体不受可破坏动物磁定向行为的磁脉冲影响。