Identification and characteristics of muscle growth-related microRNA in the Pacific abalone, Haliotis discus hannai

Abstract

Background: The Pacific abalone, Haliotis discus hannai, is the most important cultivated abalone in China. Improving abalone muscle growth and increasing the rate of growth are important genetic improvement programs in this industry. MicroRNAs are important small noncoding RNA molecules that regulate post-transcription gene expression. However, no miRNAs have been reported to regulate muscle growth in H. discus hannai. Results: we profiled six small RNA libraries for three large abalone individuals (L-HD group) and three small individuals (S-HD group) using RNA sequencing technology. A total of 205 miRNAs, including 200 novel and 5 known miRNAs, were identified. In the L-HD group, 3 miRNAs were up-regulated and 7 were down-regulated compared to the S-HD specimens. Bioinformatics analysis of miRNA target genes revealed that miRNAs participated in the regulation of cellular metabolic processes, the regulation of biological processes, the Wnt signaling pathway, ECM-receptor interaction, and the MAPK signaling pathway, which are associated with regulating growth. Bone morphogenetic protein 7 (BMP7) was verified as a target gene of hdh-miR-1984 by a luciferase reporter assay and we examined the expression pattern in different developmental stages. Conclusion: This is the first study to demonstrate that miRNAs are related to the muscle growth of H. discus hannai. This information could be used to study the mechanisms of abalone muscle growth. These DE-miRNAs may be useful as molecular markers for functional genomics and breeding research in abalone and closely related species.