Abstract：
Anadromous Pacific salmon (genus Oncorhynchus) are known for homing behavior to their natal rivers based on olfactory imprinted memories during seaward migration. The SNARE complex is a regulator of vesicle exocytosis from the presynaptic membrane. Our previous study suggested that its component genes (Snap25, Stx1, and Vamp2) are more highly expressed in the olfactory nervous system (ONS) during the migration stages associated with olfactory imprinting in the evolutionary species of Pacific salmon, such as chum (O. keta) and pink (O. gorbuscha) salmon. Masu salmon (O. masou) has a significantly different life history from these species, living longer in rivers and being a more primitive Pacific salmon species. In this study, the transcription of snare mRNAs in the ONS was analyzed using mainly male wild masu salmon. Five cDNAs encoding masu salmon SNAREs, which are well conserved among vertebrates, were isolated and sequenced. Each snare mRNA was highly expressed in age 1+ (yearling) parr prior to smoltification, particularly in the olfactory bulb. Their transcription status was significantly different from that of chum and pink salmon, which showed high expression in earlier under-yearling juveniles. The present results and our previous studies indicate that snare mRNAs are highly transcripted until the seaward migration, reflecting neural development and neuroplasticity of the ONS for olfactory imprinting.
摘要：
Anadroquous太平洋鲑鱼（Oncorhynchus属）以在向海迁移过程中根据嗅觉印记的记忆而对其出生河流的归巢行为而闻名。SNARE复合物是来自突触前膜的囊泡胞吐作用的调节剂。我们先前的研究表明，在太平洋鲑鱼进化物种中与嗅觉印记相关的迁移阶段，其组成基因（Snap25，Stx1和Vamp2）在嗅觉神经系统（ONS）中的表达更高，如密友(O.keta）和粉红色（O.Gorbuscha）鲑鱼。马苏鲑鱼（O.masou)与这些物种有着显著不同的生活史，在河流中的寿命更长，是一种更原始的太平洋鲑鱼。在这项研究中,主要使用雄性野生马苏鲑鱼分析ONS中圈套mRNA的转录。五个编码马苏鲑鱼SNARE的cDNA，在脊椎动物中非常保守，被分离并测序。每个圈套mRNA在1岁（一岁）时高度表达，特别是在嗅球中。它们的转录状态与密麻哈鱼和粉红鲑鱼的转录状态明显不同，在较早的一岁以下少年中显示出高表达。目前的结果和我们以前的研究表明，圈套mRNA高度转录，直到向海迁移，反映嗅觉印迹ONS的神经发育和神经可塑性。
