Recruitment of mitochondrial tRNA genes as auxiliary variability markers for both intra- and inter-species analysis: The paradigm of brown hare (Lepus europaeus)

We sequenced and analyzed the mitochondrial tRNA(Thr) and tRNA(Pro) genes from brown hare (Lepus europaeus) individuals of different geographic distribution and we investigated the role of various nucleotide substitutions that were detected. We compared these tRNAs with the respective available mitochondrial tRNA genes sequences within Lepus species and among mammals. The mutations that were detected represent specific and conserved polymorphisms that do not seem to affect the structural and functional features that are required for participation of tRNA molecules in mitochondrial protein synthesis. These changes however, possibly reflect on the evolutionary background of the species, which is based on the high intra-genomic variability and the evolutionary dynamic of the mitochondrial DNA. In an attempt to compare the phylogeny that is based on these specific tRNA genes with the phylogeny that is produced from sequencing data of the mitochondrial variable loop, we came up with results that indicate similar phylogeographic clusters. This observation implies that the tRNA mutations that were used for the present study have been well tolerated during evolution and they define an additional genetic and biochemical tag that can be used for such studies. Based on this notion and according to our results, we propose that mitochondrial tRNA genes can be used as valuable auxiliary molecular markers for contemporaneous and linked biochemical and genetic analyses.