Characterization of five complete Cyrtodactylus mitogenome structures reveals low structural diversity and conservation of repeated sequences in the lineage

Mitochondrial genomes (mitogenomes) of five Cyrtodactylus were determined. Their compositions and structures were similar to most of the available gecko lizard mitogenomes as 13 protein-coding, two rRNA and 22 tRNA genes. The non-coding control region (CR) of almost all Cyrtodactylus mitogenome structures contained a repeated sequence named the 75-bp box family, except for C. auribalteatus which contained the 225-bp box. Sequence similarities indicated that the 225-bp box resulted from the duplication event of 75-bp boxes, followed by homogenization and fixation in C. auribalteatus. The 75-bp box family was found in most gecko lizards with high conservation (55–75% similarities) and could form secondary structures, suggesting that this repeated sequence family played an important role under selective pressure and might involve mitogenome replication and the likelihood of rearrangements in CR. The 75-bp box family was acquired in the common ancestral genome of the gecko lizard, evolving gradually through each lineage by independent nucleotide mutation. Comparison of gecko lizard mitogenomes revealed low structural diversity with at least six types of mitochondrial gene rearrangements. Cyrtodactylus mitogenome structure showed the same gene rearrangement as found in most gecko lizards. Advanced mitogenome information will enable a better understanding of structure evolution mechanisms

Data from: A late Pleistocene marine glacial refugium in the south-west of Hainan Island, China: Phylogeographical insights from the brown alga Sargassum polycystum

Aim: Hainan Island, southern China, is characterized by rich diversity and endemism of marine organisms, yet the underpinning mechanisms and processes contributing to speciation and diversification are poorly understood. Here, the brown alga Sargassum polycystum is used as a model to identify putative marine glacial refugia and explore biogeographical patterns driven by climate change in the late Pleistocene ice ages. Location: South-East Asia. Methods: Mitochondrial cox1 and cox3 and nuclear internal transcribed spacer-2 (ITS2) were obtained from 310, 325 and 313 individuals of S. polycystum (23 localities), respectively. Phylogenetic trees (maximum likelihood and Bayesian inference) and haplotype/ribotype networks were constructed to elucidate phylogeographical patterns. Analysis of molecular variance (AMOVA), neutrality tests (Tajima's D and Fu & Li's D*), current (θπ) and historical (θw) genetic diversities and extended Bayesian skyline plots (EBSP) were used to estimate historical demography. Results: The populations from the south-west of Hainan Island harboured much higher genetic diversity and unique endemism in comparison with other populations in the distribution range. Sargassum polycystum experienced relatively long-term stable population size followed by a continued period of demographic expansion in the late Pleistocene. Main conclusions: Our phylogeographical evidence revealed the existence of a previously unidentified marine refugium specific to S. polycystum in the south-west of Hainan Island, China (the Central Depression of the Yinggehai Basin), along with a possible secondary refugium around the Bali Island, Indonesia. These biogeographical findings provide important insights regarding speciation, adaptation and evolution of marine organisms in South-East Asia and the conservation of unique biodiversity under climate change

Sampling information and sequences of three gene markers

Sampling information and sequences of three gene marker