Potential roles for microRNAs in facilitating physiological adaptation to low-temperature stress in Penaeus vannamei

Water temperature is one of the most common physiological stressors in aquaculture. Previous studies demonstrate that organisms require miRNA activity for survival in various unfavourable environmental conditions. However, the detailed role of miRNA in response to low-temperature stress is still unclear. This study was conducted to construct a comprehensive miRNA dataset for the Penaeus vannamei after low-temperature stress. A total of 329 known miRNAs and 60 putative novel miRNAs were identified. Among them, 17 miRNAs were identified with the most significant differences, and they were found to be involved in stimulation or stress processes. The main enriched target pathways of the 17 miRNAs were the Hippo signalling pathway, autophagy, apoptosis and MAPK signalling. In addition, all the 17 miRNAs identified were up-regulated, suggesting that miRNA by inhibiting the expression of target genes constitutes an effective strategy for Penaeus vannamei to cope with low-temperature stress. The 35-putative target of the 17 miRNAs was related to apoptosis and autophagy-related proteins, such as Pxt, DRAM2, cytochrome c, ATG2B, JNK, ATG4 and API5. The analysis of miRNA expression profiles contributes to the understanding of the molecular mechanisms of low-temperature tolerance in Penaeus vannamei. This study's findings enrich current miRNA resources and offer the possibility to validate the involvement of 17 miRNAs in the response of shrimp to low-temperature stress.