Large-scale identification and comparative analysis of miRNA expression profile in the respiratory tree of the sea cucumber Apostichopus japonicus during aestivation (part 1)

ABSTRACT: The sea cucumber Apostichopus japonicus withstands high water temperatures in the summer by suppressing metabolic rate and entering a state of aestivation. We hypothesized that changes in the expression of miRNAs could provide important post-transcriptional regulation of gene expression during hypometabolism via control over mRNA translation. The present study analyzed profiles of miRNA expression in the sea cucumber respiratory tree using Solexa deep sequencing technology. We identified 279 sea cucumber miRNAs, including 15 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 an active state). We identified 30 differentially expressed miRNAs ([RPM (reads per million) >10, |FC| (|fold change|) M-bM-^IM-%1, FDR (false discovery rate) <0.01]) during aestivation, which were validated by two other miRNA profiling methods: miRNA microarray and real-time PCR. Among the most prominent miRNA species, miR-124, miR-124-3p, miR-79, miR-9 and miR-2010 were significantly over-expressed during deep aestivation compared with non-aestivation animals, suggesting that these miRNAs may play important roles in metabolic rate suppression during aestivation. In the present study, an analysis of the global profile of small RNAs was conducted using Solexa sequencing technology in non-aestivation (NA) and deep aestivation (DA) sea cucumbers. We focus on respiratory tree in the present study because it is the important site responsible for the strong metabolic rate depression seen under deep aestivating conditions and the global expression profile of mRNA from the this organ has also been constructed applying RNA-seq technology in our previous study (Zhao and Chen, unpublished data). A preliminary analysis of the functional relevance of miRNA expression in relation to hypometabolism during aestivation is presented. A miRNA microarray and RT-qPCR were both used to supplement and confirm differentially expressed miRNAs. Our findings provide important new insights into the molecular mechanisms of sea cucumber aestivation.

ORGANISM(S): Apostichopus japonicus

SUBMITTER: Muyan Chen 

PROVIDER: E-GEOD-52224 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress