microRNAs as determinants of metabolic phenotypes in teleost fish

硬骨鱼是脊椎动物中最大的亚类，具有独特的生态位，并表现出多种代谢表型。分子因素在硬骨鱼的整个生命周期和世代中塑造生物体代谢表型。这项研究调查了一类称为microRNA（miRNAs）的特定分子在成年硬骨鱼及其发育和世代中形成代谢表型的作用。miRNA是短的非蛋白质编码基因产物，其通过与靶向mRNA的互补碱基配对降低mRNA稳定性并抑制其翻译。现在被认为是哺乳动物代谢的有效调节剂，它们在硬骨鱼中的比较作用的特点很差。我们的研究将确定miRNAs在虹鳟鱼和斑马鱼这两个物种中的作用，这两个物种非常适合确定miRNAs在成年硬骨鱼中独特的代谢表型中的作用，并分别跨越发育和世代。虹鳟鱼具有独特的代谢表型，因为它们耐受持续禁食，并且不耐受富含葡萄糖的饮食。由于最近公布的虹鳟鱼基因组，我们现在处理的详细特征的miRNAs在这个物种和生物信息学工具来预测调控目标。因此，我们将使用虹鳟鱼，在代谢的比较生理学的一个完善的模型，以确定调控和功能的miRNA，包括物种特异性的miRNA，在其独特的代谢表型。为了解决miRNAs在发育和世代中的代谢作用，我们将使用斑马鱼，一种具有短世代时间的发育模型。我们将确定营养代谢刺激物在基线条件下或响应于额外的代谢刺激物的成人和跨代代谢表型的早期发育中的作用。通过确定发育过程中和配子中的差异miRNA表达，以及通过调节鉴定的miRNA候选物的胚胎表达，将确定miRNA在这些时间尺度上代谢表型出现中的作用。总之，这些方法将提供比较深入的了解miRNA分子在硬骨鱼的生理代谢中的作用，这对水产养殖育种计划和营养，以及在加拿大环境中关注的鲤鱼和鲑鱼物种的生态毒理学具有重要意义。

Bony fishes, the largest vertebrate infraclass, have evolved to inhabit unique ecological niches and exhibit a great variety of metabolic phenotypes. Molecular factors shape organismal metabolic phenotypes in bony fishes across the lifecycle and generations. This research investigates the role of a specific class of molecules called microRNAs (miRNAs) in shaping metabolic phenotypes in adult bony fishes and across their development and generations. miRNAs are short, non-protein coding gene products which decrease mRNA stability and inhibit their translation through complementary base pairing with targeted mRNAs. Now regarded as potent regulators of metabolism in mammals, their comparative role in bony fishes is poorly characterized. Our research will determine the role of miRNAs in two species, rainbow trout and zebrafish, which are well suited to determine the role of miRNAs in unique metabolic phenotypes in adult bony fishes and across development and generations, respectively. Rainbow trout possess a unique metabolic phenotype in that they tolerate sustained fasting and are intolerant to glucose-rich diets. Since the recent publication of the rainbow trout genome, we now dispose of a detailed characterization of miRNAs in this species and bioinformatics tools to predict regulated targets. We will thus use rainbow trout, a well-established model in the comparative physiology of metabolism, to determine regulation and function of miRNAs, including species-specific miRNAs, in its unique metabolic phenotype. To address metabolic roles of miRNAs across development and generations, we will use zebrafish, a developmental model with short generational time. We will determine the role of nutritional metabolic stimuli in early development on adult and trans-generational metabolic phenotypes under baseline conditions or in response to additional metabolic stimuli. The role of miRNAs in the emergence of metabolic phenotypes across these timescales will be determined by determining differential miRNA expression across development and in gametes, and by modulating embryonic expression of identified miRNA candidates. Together, these approaches will provide comparative insight into the role of miRNA molecules in the physiology metabolism in bony fish, which has important implication for aquaculture breeding programs and nutrition, as well as ecotoxicology of cyprinid and salmonid species of concern in the Canadian environment.