Evolutionary insights into micrornas of kiwifruit actinidia Chinensis and its close relatives

The advent of next-generation sequencing technologies and newly developed bioinformatics tools have provided us complete sequence information of organisms. Plant microRNAs (miRNAs), small non-coding RNAs about 21-24 nucleotides, and their regulatory roles in biological processes have been uncovered since the identification of the first miRNA. MicroRNA biogenesis and modes of actions have also been elucidated in previous studies. In the presented study, we identified putative microRNAs from Actinidia chinensis, Arabidopsis thaliana, Solanum lycopersicum, Solanum tuberosum and Vitis vinifera to compare their miRNA repertoire. According to the results, the highest synteny was found between V.vinifera-A.chinensis and the least synteny was found between A.thalianaA.chinensis. The highest number of putative miRNAs were identified from A.thaliana whereas the least amount of putative miRNAs were identified from V.vinifera. This may be depended on the size of the genomes. We also analyzed the targets of putatively identified miRNAs for each organism. Expectedly, the target pathways of the predicted putative miRNAs were similar between the closest organisms. Expressed miRNA families and copy number of miRNA genes were compared between all organisms. In A.thaliana, the number of expressed putative miRNAs are more than the other organisms. For all the organisms, different miRNA families had the high copy number of genes. Therefore, highly represented miRNA families on each genome may have specific functional roles. The findings in this study will help the research community to identify the roles of miRNA players on critical biological pathways