Carassius auratus red var. miRNA transcriptome

The bisexual fertile tetraploid fish is important in biological evolution. Tetraploid fish fertility is the key factor for stable inheritance. Therefore, elucidating tetraploid fish fertility at the molecular level is essential. MicroRNAs regulate gene expression and are involved in many aspects of gonad development. In this study, allotetraploid hybrid fish (4nAT) and diploid red crucian carp (RCC) ovaries were used to compare miRNA profiles. The results indicated that most of the highly expressed miRNAs were closely correlated with ovary maturation, and displayed no significant differences in expression. Moreover, 34 up-regulated and 9 down-regulated miRNAs were found in 4nAT. The differentially expressed miRNAs were primarily involved in metabolism, defense mechanisms, and cytoskeleton production. This is the first study to provide new epigenetic evidence for tetraploid fish fertility and phenotypic changes as a result of increased ploidy.