First characterization and validation of turbot microRNAs

ROBLEDO, DIEGO; MARTIN, ANA PAULA; ÁLVAREZ-DIOS, JOSÉ ANTONIO; BOUZA, CARMEN; PARDO, BELÉN GÓMEZ; MARTÍNEZ, PAULINO

AQUACULTURE

ELSEVIER SCIENCE BV

Año: 2015

0044-8486

MicroRNAs (miRNAs) are highly conserved short non-coding RNAs which play a key role in a wide array of processes. They are usually at the center of regulatory networks modulating the expression of a large number of mRNAs. miRNAs have been found to regulate processes related to relevant aquaculture traits like growth or immune response; hence characterizing and studying the miRNA repertoire in farmed species is interesting for aquaculture purposes. Turbot (Scophthalmus maximus) is a commercially important flatfish characterized by adult bilateral asymmetry after larvae undergo metamorphosis during early development. Diverse turbot tissues from different developmental stages were pooled and sequenced for small RNA identification. A total of 306 turbot mature miRNAs, 299 known and 7 not previously described, were identified, placed on the turbot genome, and their precursor sequences predicted. Among them, 15 miRNAs involved in growth, immunity or sex differentiation processes and three novel microRNAs were technically validated along turbot early development (5, 15, 25, 35. days post fertilization), encompassing endogenous to exogenous feeding transition and metamorphosis. Most of the selected miRNAs showed expression changes among tested stages. Then, putative mRNAs targets for these 18 miRNAs were identified by screening the turbot transcriptome using two different predictive algorithms. In summary, this is the first description of the turbot miRNA repertoire, which will be useful for future studies aiming to improve turbot aquaculture production, but also it represents a contribution to understand teleost miRNAs function. Statement of relevance: MicroRNAs are usually found in the center of regulatory networks, hence their characterization and study are critical for understanding a broad array of biological processes. The findings reported here - miRNA sequencing, characterization, mapping to the genome, validation of relevant and novel miRNAs and target prediction are an important resource for aquaculture, since understanding the involvement in immunology, growth or sex differentiation of these microRNAs can increase the knowledge on the physiology of these processes, which is important to better manipulate these traits and improve aquaculture production.