Elucidation of molecular mechanism of indeterminate growth of skeletal muscle in fish

斑马鱼和大鼠衰老相关DEG谱的对比分析显示，衰老现象既保守又明显不同。我们的研究结果显示了鱼类和哺乳动物之间的共同和不同的衰老特征。用差速离心和商用试剂盒分离外泌体。从3个年龄组罗非鱼血清外泌体中分离RNA后，使用Agilent 2100生物分析仪分析外泌体小RNA的质量和大小分布，清晰地显示了miRNA的选择。在确认RNA质量后，成功构建了来自3个年龄组的12个外泌体小RNA文库，并通过HiSeq 2500测序对其进行测序，以调查miRNA多样性。在去除已知的rna和基因组未映射的reads后，本研究还剩下1426万个reads用于miRNA鉴定。为了鉴定不同年龄组罗非鱼外泌体中的已知mirna，我们将我们的数据集与miRBase 22.0中的已知mirna进行了比较。允许序列之间不超过一个不匹配，鉴定了80个已知的mirna。为了研究mirna对衰老的影响，我们将对选定的特征mirna的靶基因以及三个年龄组中最丰富的mirna进行预测。从Gene Ontology数据库中对目标基因进行GO注释，p值阈值为0.05，进行功能分析。计划研究的结果将有助于首次确定外泌体相关mirna在硬骨鱼衰老过程中的新作用。

Comparative analysis of DEG profiles associated with aging between zebrafish and rat showed both conserved and clearly different aging phenomena. Our results indicate both common and different aging profiles between fish and mammals.Exosomes were isolated with differential centrifugation and commercial kit. After isolation of RNA from the serum exosome of three age-group of tilapia, we analyzed the quality and size distribution of the exosomal small RNA by using Agilent 2100 Bioanalyzer, which clearly showed the miRNA picks. After confirming the RNA quality, twelve exosomal small RNA libraries from the three age groups were successfully constructed and sequenced by HiSeq 2500 sequencing to survey the miRNA diversity. After removing known RNAs and genome unmapped reads, 14.26 million reads were remaining for miRNA identification in this study. To identify known miRNAs in the exosome of different age-group tilapia, we compared our dataset with the known miRNAs in miRBase 22.0. Allowing no more than one mismatch between sequences, 80 known miRNAs were identified. For the purpose of investigating the influence of miRNAs on the aging, the target genes of the selected signature miRNAs as well as most abundant miRNAs in the three age-groups will be predicted. GO annotation of target genes will be conducted from Gene Ontology database with p-value threshold of 0.05 for their function analysis. The outcomes of the planned research would facilitate to identify the new and novel roles of exosome-associated miRNAs, which are involved in aging in the teleost for the first time.