Mitogenomic Analysis of Glirids (Gliridae) and Squirrels (Sciuridae) From Türkiye: Evolutionary and Taxonomic Implications Within the Suborder Sciuromorpha

Gliridae and Sciuridae, the most impressive mammalian radiations within the suborder Sciuromorpha, encompass a total of 327 extant species. This study aimed to: (i) characterize the mitogenomes of three sciurid (Spermophilus citellus, Spermophilus taurensis, and Spermophilus xanthoprymnus) and three glirid (Glis glis, Dryomys nitedula, and Dryomys laniger) species from Türkiye; (ii) elucidate the phylogeographic relationships within D. laniger and D. nitedula using both mitogenomes and mitochondrial cytochrome b (CYTB) sequences; and (iii) reconstruct the phylogenetic relationships among extant members of the suborder Sciuromorpha. Sixteen new mitogenomes were sequenced from Turkish samples, containing 37 genes (2 ribosomal RNAs, 13 protein-coding genes, 22 transfer RNAs), exhibiting similarity to those of other Gliridae and Sciuridae species. Based on mitogenomic data, Bayesian Inference and Maximum Likelihood phylogenetic analyses revealed two major phylogroups corresponding to the two families, Gliridae and Sciuridae, which were both monophyletic. Analyses of mitogenomic and CYTB sequences revealed at least two major lineages (i: Anatolia and ii: Lesser Caucasus and Alborz) of D. nitedula in the Anatolian region of Türkiye. The mitochondrial CYTB data indicated that D. laniger exhibited at least two major lineages (Eastern and Western), whereas D. nitedula comprised multiple lineages and sublineages. The mean genetic distance between the two mitogenomic lineages of D. nitedula was 7.69%. Based on the CYTB data, the mean genetic distance between the Eastern and Western lineages of D. laniger was 7%, whereas the mean genetic distances among the lineages of D. nitedula ranged from 6% to 13%. Major lineages of both D. laniger and D. nitedula might be considered distinct species throughout the species' range. This study demonstrates that complete mitogenomes for reconstructing the Gliridae phylogeny provides important information for revealing phylogenetic and phylogeographic relationships.

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.

The story of a rock-star: multilocus phylogeny and species delimitation in the starred or roughtail rock agama, Laudakia stellio (Reptilia: Agamidae)

Situated at the junction of three continents, Europe, Asia and Africa, the Eastern Mediterranean is an ideal region to study the effects of palaeogeography, ecology and long human presence on animal evolution. Laudakia stellio (Squamata: Agamidae) is found across this region and offers an excellent opportunity for such studies. The high morphological variation across their range suggests that these lizards might represent a species complex. This is the first study exploring their evolutionary history, using molecular markers and individuals from all described subspecies. We employed the latest phylogenetic and species-delimitation methods to identify all distinct evolutionary lineages, their genetic variation and divergence times. The phenotypical diversity of L. stellio matches its genetic differentiation: almost all subspecies correspond to well-supported retrieved subclades and additional distinct lineages representing intermediate morphs have been retrieved. ‘Laudakia stellio’ represents three distinct evolutionary entities that diverged during the Plio-Pleistocene transition, which we propose as distinct species. One includes Greek and Turkish populations, as well as cryptic Anatolian lineages. The second comprises all other Near East populations and the third is endemic to Cyprus. Our results indicate a role of humans in shaping present distribution patterns, and highlight the importance of the Aegean, Anatolia and the Levant as glacial refugia and diversity hotspots.

Mitogenome Phylogeny Including Data from Additional Subspecies Provides New Insights into the Historical Biogeography of the Eurasian lynx Lynx lynx

Previous molecular studies of the wide-ranging Eurasian lynx Lynx lynx focused mainly on its northern Palearctic populations, with the consequence that the reconstruction of this species’ evolutionary history did not include genetic variation present in its southern Palearctic distribution. We sampled a previously not considered Asian subspecies (L. l. dinniki), added published data from another Asian subspecies (L. l. isabellinus), and reassessed the Eurasian lynx mtDNA phylogeny along with previously published data from northern Palearctic populations. Our mitogenome-based analyses revealed the existence of three major clades (A: Central Asia, B: SE Europe/SW Asia, C: Europe and Northern Asia) and at least five lineages, with diversification in Lynx lynx commencing at least 28kyr earlier than hitherto estimated. The subspecies L. l. isabellinus harbors the most basal matriline, consistent with the origin of Lynx lynx in this subspecies’ current range. L. l. dinniki harbors the second most basal matriline, which is related to, and may be the source of, the mtDNA diversity of the critically endangered Balkan lynx L. l. balcanicus. Our results suggest that the Anatolian peninsula was a glacial refugium for Eurasian lynx, with previously unconsidered implications for the colonization of Europe by this species.