Identification of microRNA elements from genomic data of European hazelnut (Corylus avellana L.) and its close relatives

Plant microRNAs (miRNAs) are small and non-coding endogenous RNAs which have numerous regulatory roles in cells. These critical players regulate pathways either by inducing translational repression or messenger RNA (mRNA) decay. Newly developed bioinformatics tools and computational methods have been increased to identify miRNAs with their targets inside the genome. In this study, we predicted and identified 57 putative miRNAs through Corylus avellana (C. avellana) genomic data in silico. We also predicted some other putative miRNAs from Arabidopsis thaliana (A. thaliana), Ricinus communis (R. communis), Populus trichocarpa (P. trichocarpa) and Vitis vinifera (V. vinifera) to compare with the C. avellana organism since previous studies have indicated high similarities between these genomes and proteome atlases. The miRBase 21 was used as a reference dataset and the putative miRNAs were identified for the genome of each organism. We used homology conserved method to identify putative miRNAs. Based on our findings, C. avellana miRNA content was found to be highly similar to V. vinifera, R. communis and P. trichocarpa. Also, we found the targets of these hazelnut putative miRNAs and their possible functions inside the cell. One of our major discoveries is that miR171 families are highly represented (the copy number of miRNA) in the hazelnut genome to provide clues for microRNA domestication. The miR396, miR482, and miR2118 families were found as in silico expressed putative miRNAs by using computational methods. All these findings may help us better understanding the miRNA repertoire of the hazelnut organism and provide valuable insight about the regulatory roles of predicted putative miRNAs which are shared with other organisms (A. thaliana, R. communis, P. trichocarpa, V. vinifera) for further studies.