mRNA and microRNA transcriptomics analyses in intermuscular bones of two carp species, rice flower carp (Cyprinus carpio var. Quanzhounensis) and Jian carp (Cyprinus carpio var. Jian).

The rice flower carp (Cyprinus carpio var. Quanzhounensis) is a bony fish (superclass Osteichthyes), with very soft bones that is a significant feature unlike the other carp species. In this study, we analyzed the mRNA and microRNA (miRNA) transcriptomes in the intermuscular bones of rice flower carp and Jian carp (Cyprinus carpio var. Jian) (a typical member of common carp in China), using Illumina RNA sequencing. We identified 55,340 genes (including 47,541 known genes and 8231 predicted new genes) and 662 miRNAs (including 595 known miRNAs and 67 novel miRNAs) in the two species. By comparing the transcriptomes of the two species, we identified 1523 differentially expressed genes (DEGs) (including 576 up - and 947 downregulated DEGs) and 352 differentially expressed miRNAs (DEMs) (including 85 up- and 267 downregulated DEMs). According to the Gene Ontology (GO) annotation, 7 DEGs and 12 DEMs were found to be involved in the regulation of bone mineralization. The results of this study improve our understanding of the mRNA and miRNA profiles of carp bones, particularly those of the rice flower carp.