Whole mitochondrial genome sequence and phylogenetic relationships of Williams's jerboa (Scarturus williamsi) from Turkey

Characterization of Two New Apodemus Mitogenomes (Rodentia: Muridae) and Mitochondrial Phylogeny of Muridae

Apodemus is the most common small rodent species in the Palearctic realm and an ideal species for biogeographical research and understanding environmental changes. Elucidating phylogenetic relationships will help us better understand species adaptation and genetic evolution. Due to its stable structure, maternal inheritance, and rapid evolution, the mitogenome has become a hot spot for taxonomic and evolutionary studies. In this research, we determined the mitochondrial genome of Apodemus agrarius ningpoensis and Apodemus draco draco and studied the phylogeny of Muridae using ML and BI trees based on all known complete mitogenomes. The mitochondrial genome of Apodemus agrarius ningpoensis was 16,262 bp, whereas that of Apodemus draco draco was 16,222 bp, and both encoded 13 protein-coding genes, 2 ribosomal RNA genes, and 22 transfer RNA genes. Analysis of base composition showed a clear A-T preference. All tRNAs except tRNASer and tRNALys formed a typical trilobal structure. All protein-coding genes contained T- and TAA as stop codons. Phylogeny analysis revealed two main branches in the Muridae family. Apodemus agrarius ningpoensis formed sister species with Apodemus chevrieri, whereas Apodemus draco draco with Apodemus latronum. Our findings provide theoretical basis for future studies focusing on the mitogenome evolution of Apodemus.

Complete mitogenomes of Turkish tree squirrels, Sciurus anomalus and S. vulgaris, (Sciuridae: Rodentia: Mammalia) and their phylogenetic status within the tribe Sciurini

The genus Sciurus, a member of the family Sciuridae, is widely distributed in the Holarctic region. To better understand mitogenomic characteristics and to reveal internal phylogenetic relationships of the genus, 20 complete mitogenomes of Turkish tree squirrels were successfully sequenced for the first time, including 19 for S. anomalus (from 16,505 bp to 16,510 bp) and one for S. vulgaris (16,511 bp). The mitogenomes of two species were AT-biased. All tRNAs for two species displayed a typical clover-leaf structure, except for tRNA^Ser(AGY). The tRNA Serine1 (S1)-GCT structure lacked the dihydrouridine (DHU) loop and stem. Based on mitogenomic dataset for phylogeny of Sciurinae, phylogenetic analyses (Bayesian Inference and Maximum Likelihood) did not support monophyly of Sciurus and proposed that S. anomalus, the most basal taxa in the Sciurini tribe, had at least five mitogenome lineages, which were also supported by network analysis. The dissimilarities among the five linegaes of S. anomalus ranged from 0.0042 (0.42%) to 0.0062 (0.62%) using K2P sequence pairwise distances. In addition to this mitogenomic analysis result, phylogenetic analyses using the CYTB + D-loop dataset proposed the existence of at least nine lineages for S. anomalus, which was different than those of the previous studies. The current study proposed that the use of mitogenomic data for reconstructing the phylogeny of Turkey' Sciurus holds an important value for revealing evolutionary relationships.

Characterisation of the Complete Mitochondrial Genome of Critically Endangered Mustela lutreola (Carnivora: Mustelidae) and Its Phylogenetic and Conservation Implications

In this paper, a complete mitochondrial genome of the critically endangered European mink Mustela lutreola L., 1761 is reported. The mitogenome was 16,504 bp in length and encoded the typical 13 protein-coding genes, two ribosomal RNA genes and 22 transfer RNA genes, and harboured a putative control region. The A+T content of the entire genome was 60.06% (A > T > C > G), and the AT-skew and GC-skew were 0.093 and −0.308, respectively. The encoding-strand identity of genes and their order were consistent with a collinear gene order characteristic for vertebrate mitogenomes. The start codons of all protein-coding genes were the typical ATN. In eight cases, they were ended by complete stop codons, while five had incomplete termination codons (TA or T). All tRNAs had a typical cloverleaf secondary structure, except tRNA^Ser(AGC) and tRNA^Lys, which lacked the DHU stem and had reduced DHU loop, respectively. Both rRNAs were capable of folding into complex secondary structures, containing unmatched base pairs. Eighty-one single nucleotide variants (substitutions and indels) were identified. Comparative interspecies analyses confirmed the close phylogenetic relationship of the European mink to the so-called ferret group, clustering the European polecat, the steppe polecat and the black-footed ferret. The obtained results are expected to provide useful molecular data, informing and supporting effective conservation measures to save M. lutreola.

Complete mitochondrial genome characterization and phylogenetic analyses of the main vector of Crimean-Congo haemorrhagic fever virus: Hyalomma marginatum Koch, 1844

The Mediterranean tick, Hyalomma marginatum, is the most important vector of Crimean-Congo haemorrhagic fever virus and several pathogens that cause animal and human diseases and economic losses to livestock production. Given the medical and veterinary importance of this tick species, we sequenced and characterized its mitochondrial genome (mitogenome) for the first time. We designed two new primer sets and combined long-range PCR with next generation sequencing to generate complete mitogenomes with deep coverage from 10 H. marginatum adults. The mitogenomes contained 13 protein-coding genes (PCGs), 22 transfer RNAs (tRNAs), two ribosomal subunits, two control regions, and three tick-box motifs. The nucleotide composition of the H. marginatum mitogenomes were A+T biased (79.76%) and exhibited negative AT- and GC- skews across most PCGs. All PCGs were initiated by ATK codons and two truncated termination codons were seen in the COX2 and COX3 genes. All tRNAs exhibited typical cloverleaf structures, except for tRNA^Cys and tRNA^Ser1. A total of 62 polymorphic sites defined ten unique haplotypes. Phylogenetic analyses based on the 13 PCGs of 56 tick species revealed that four Hyalomma species (H. marginatum, H. asiaticum, H. rufipes, and H. truncatum) formed a monophyletic clade with strong support. The results of this study provide a comprehensive resource for further studies on the systematics, population genetics, molecular epidemiology, and evolution of ticks.