Identification and expression profiling of microRNAs in brain, liver and gonads of marine medaka (Oryzias melastigma) by Illumina small RNA Sequencing

We performed miRNA transcriptome analysis of mature medaka tissues using high-throughput next generation sequencing technology. The small RNA libraries were contructed from brain, liver and gonads in mature male and female medaka and a total of more than 128 million sequencing reads were generated from the six small RNA libraries. By comparison to known miRNA database, a total of 223 known miRNA types were identified with more than 50% expressed in brain. The expression profiling showed that almost half of the miRNAs are tissue-specific, with only 55 miRNA types from 34 families common to all tissues. A small number of miRNAs are also gender-specific. The experimental validation was performed for five represented miRNA candidates and four of them are confirmed. Overall design: Investigation of miRNA expression profiles from three tissues (brain, liver and gonads) of mature male and female medaka.

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