microRNA expression profile of fish erythrocytes

Abstract

MicroRNAs (miRNAs) are short noncoding sequences that can regulate the expression of target genes. Erythrocytes, also called red blood cells (RBCs), are the largest proportion of cells in blood. Erythrocytes deliver oxygen in the body of vertebrates and contribute to the body's immune function. Illumina sequencing technology was used to analyze pooled RNA samples isolated from erythrocytes, in order to characterize their gene expression profile and increase the range of miRNAs identified in Nile tilapia erythrocytes. This study identified conserved (n = 309) and novel (n = 194) miRNAs. Quantitative reverse-transcription polymerase chain reaction and next-generation sequencing results indicated that miR-451 was the most abundant in RBCs, followed by let-7a-1, miR-2188 and miR-144. Moreover, the tissue expression mode of these highly expressed miRNAs was characterized. Results show that miR-451, miR-2188, and miR-144 were all highly expressed in RBCs but were low abundance in other tissues. miR-1 and miR-10b were also abundantly expressed in muscle, while miR-122 was abundantly expressed in the liver. let-7a-1, miR-10b, and miR-1 were significantly higher in the testis than in the ovary. The tissue distribution of miRNAs implies that these noncoding sequences have a potential role in regulating tissue differentiation or maintaining tissue characteristics. The results of a dual-luciferase reporter assay indicated that miR-144 and miR-10b inhibited the expression of the meningioma expressed antigen 5 gene in vitro. This study contributes to the Nile tilapia miRNA database and reveals the profile of erythrocyte miRNA expression.

Keywords

• Erythrocyte
• miRNA
• MGEA5
• miR-144
• miR-10b
• Nile tilapia