Profiling microRNA expression in Atlantic killifish (Fundulus heteroclitus) gill and responses to arsenic and hyperosmotic stress

The Atlantic killifish (Fundulus heteroclitus), native to estuarine areas of the Atlantic coast of the United States, has become a valuable ecotoxicological model due to its ability to acclimate to rapid environmental changes and adapt to polluted habitats. Killifish respond to rapid increases in salinity with an immediate change in gene expression, as well as long-term remodeling of the gills. Arsenic, a major environmental toxicant, was previously shown to inhibit the ability of killifish gill to respond to a rapid increase in salinity. We characterized miRNA expression in killifish gill under salinity acclimation with and without arsenic and identified a small group of highly expressed, well-conserved miRNAs as well as 16 novel miRNAs not yet identified in other organisms. Overall design: Small RNA gene expression profiling in the gill during salinity acclimation (0, 1 and 24 hours post-transition to seawater) with and without 100 ug/L arsenic (sodium (meta)arsenite).大西洋鳉（Fundulus heteroclitus）原生分布于美国大西洋沿岸的河口区域，因其具备快速适应环境变化、耐受污染生境的能力，已成为极具应用价值的生态毒理学模型生物。鳉鱼可对盐度的快速升高产生即时的基因表达变化，同时伴随鳃组织的长期结构重塑。砷作为一类主要的环境有毒污染物，此前已有研究证实其能够抑制鳉鱼鳃组织响应盐度快速升高的能力。本研究对暴露于100 μg/L亚砷酸钠与未暴露砷的鳉鱼鳃组织，在盐度驯化过程中的miRNA（microRNA）表达谱进行了系统表征，鉴定出一组高表达、高度保守的miRNA，以及16种尚未在其他生物中被发现的新型miRNA。整体实验设计：在盐度驯化过程中（过渡至海水后的0、1及24小时），对暴露与未暴露100 μg/L亚砷酸钠的鳉鱼鳃组织开展小分子RNA基因表达谱分析。