Bao Weier, Greenwold Matthew J, Sawyer Roger H
Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA.
Gene. 2016 Oct 15;591(2):393-402. doi: 10.1016/j.gene.2016.06.027. Epub 2016 Jun 15.
MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression at the post-transcriptional level. Previous studies have shown that miRNA regulation contributes to a diverse set of processes including cellular differentiation and morphogenesis which leads to the creation of different cell types in multicellular organisms and is thus key to animal development. Feathers are one of the most distinctive features of extant birds and are important for multiple functions including flight, thermal regulation, and sexual selection. However, the role of miRNAs in feather development has been woefully understudied despite the identification of cell signaling pathways, cell adhesion molecules and structural genes involved in feather development. In this study, we performed a microarray experiment comparing the expression of miRNAs and mRNAs among three embryonic stages of development and two tissues (scutate scale and feather) of the chicken. We combined this expression data with miRNA target prediction tools and a curated list of feather related genes to produce a set of 19 miRNA-mRNA duplexes. These targeted mRNAs have been previously identified as important cell signaling and cell adhesion genes as well as structural genes involved in feather and scale morphogenesis. Interestingly, the miRNA target site of the cell signaling pathway gene, Aldehyde Dehydrogenase 1 Family, Member A3 (ALDH1A3), is unique to birds indicating a novel role in Aves. The identified miRNA target site of the cell adhesion gene, Tenascin C (TNC), is only found in specific chicken TNC splice variants that are differentially expressed in developing scutate scale and feather tissue indicating an important role of miRNA regulation in epidermal differentiation. Additionally, we found that β-keratins, a major structural component of avian and reptilian epidermal appendages, are targeted by multiple miRNA genes. In conclusion, our work provides quantitative expression data on miRNAs and mRNAs during feather and scale development and has produced a highly diverse, but manageable list of miRNA-mRNA duplexes for future validation experiments.
微小RNA（miRNA）是一类小的非编码RNA，它们在转录后水平调控基因表达。先前的研究表明，miRNA调控参与了多种过程，包括细胞分化和形态发生，这些过程导致多细胞生物中不同细胞类型的产生，因此是动物发育的关键。羽毛是现存鸟类最显著的特征之一，对于包括飞行、体温调节和性选择在内的多种功能都很重要。然而，尽管已经鉴定出参与羽毛发育的细胞信号通路、细胞粘附分子和结构基因，但miRNA在羽毛发育中的作用却鲜有研究。在本研究中，我们进行了一项微阵列实验，比较了鸡的三个胚胎发育阶段和两种组织（盾鳞和羽毛）中miRNA和mRNA的表达。我们将这些表达数据与miRNA靶标预测工具以及一份精心整理的羽毛相关基因列表相结合, 生成了一组19个miRNA-mRNA双链体。这些靶向的mRNA先前已被鉴定为重要的细胞信号和细胞粘附基因，以及参与羽毛和鳞片形态发生的结构基因。有趣的是，细胞信号通路基因醛脱氢酶1家族成员A3（ALDH1A3）的miRNA靶位点是鸟类特有的，表明其在鸟类中具有新的作用。细胞粘附基因腱生蛋白C（TNC）的已鉴定miRNA靶位点仅在特定的鸡TNC剪接变体中发现，这些变体在发育中的盾鳞和羽毛组织中差异表达，表明miRNA调控在表皮分化中具有重要作用。此外，我们发现β-角蛋白是鸟类和爬行动物表皮附属器的主要结构成分，被多个miRNA基因靶向。总之，我们的工作提供了羽毛和鳞片发育过程中miRNA和mRNA的定量表达数据，并生成了一份高度多样化但易于管理的miRNA-mRNA双链体列表，用于未来的验证实验。
