High-Throughput Sequencing Reveals Differential Expression of miRNAs in Intestine from Sea Cucumber during Aestivation

The regulatory role of miRNA in gene expression is an emerging hot new topic in the control of hypometabolism. Sea cucumber aestivation is a complicated physiological process that includes obvious hypometabolism as evidenced by a decrease in the rates of oxygen consumption and ammonia nitrogen excretion, as well as a serious degeneration of the intestine into a very tiny filament. To determine whether miRNAs play regulatory roles in this process, the present study analyzed profiles of miRNA expression in the intestine of the sea cucumber (Apostichopus japonicus), using Solexa deep sequencing technology. We identified 308 sea cucumber miRNAs, including 18 novel miRNAs specific to sea cucumber. Animals sampled during deep aestivation (DA) after at least 15 days of continuous torpor, were compared with animals from a non-aestivation (NA) state (animals that had passed through aestivation and returned to the active state). We identified 42 differentially expressed miRNAs [RPM (reads per million) >10, |FC| (|fold change|) ≥1, FDR (false discovery rate)

微小RNA（miRNA）在基因表达中的调控作用，是低代谢调控领域的新兴热门研究课题。海参夏眠是一类复杂的生理过程，其伴随显著的低代谢状态——具体表现为耗氧速率与氨氮排泄率下降，同时肠道发生严重退化，缩为极细小的丝状结构。为明确miRNA在该过程中是否发挥调控作用，本研究采用Solexa深度测序技术，对仿刺参（Apostichopus japonicus）肠道的miRNA表达谱进行了分析。本研究共鉴定出308条海参来源的miRNA，其中包含18条海参特异性的新型miRNA。研究以至少连续蛰伏15天后的深度夏眠组（DA）海参为样本，与非夏眠组（NA）——即完成夏眠并恢复至活跃状态的海参——进行对照比较。最终鉴定出42个差异表达miRNA，筛选标准为：RPM（reads per million，每百万读段数）>10、|FC|（fold change，折叠变化倍数）≥1、FDR（false discovery rate，错误发现率）