Mauremys reevesii

Raw data of <i>Mauremys reevesii</i> transcriptom

De novo assembly and characterization of the Chinese three-keeled pond turtle (Mauremys reevesii) transcriptome: presence of longevity-related genes

Mauremys reevesii (Geoemydidae) is one of the most common and widespread semi-aquatic turtles in East Asia. The unusually long lifespan of some individuals makes this turtle species a potentially useful model organism for studying the molecular basis of longevity. In this study, pooled total RNA extracted from liver, spleen and skeletal-muscle of three adult individuals were sequenced using Illumina Hiseq 2500 platform. A set of telomere-related genes were found in the transcriptome, including tert, tep1, and six shelterin complex proteins coding genes (trf1, trf2, tpp1, pot1, tin2 and rap1). These genes products protect chromosome ends from deterioration and therefore significantly contribute to turtle longevity. The transcriptome data generated in this study provides a comprehensive reference for future molecular studies in the turtle

The Historical Speciation of <i>Mauremys</i> Sensu Lato: Ancestral Area Reconstruction and Interspecific Gene Flow Level Assessment Provide New Insights

<div><p><i>Mauremys</i> sensu lato was divided into <i>Mauremys</i>, <i>Chinemys</i>, <i>Ocadia</i>, and <i>Annamemys</i> based on earlier research on morphology. Phylogenetic research on this group has been controversial because of disagreements regarding taxonomy, and the historical speciation is still poorly understood. In this study, 32 individuals of eight species that are widely distributed in Eurasia were collected. The complete mitochondrial (mt) sequences of 14 individuals of eight species were sequenced. Phylogenetic relationships, interspecific divergence times, and ancestral area reconstructions were explored using mt genome data (10,854 bp). Subsequent interspecific gene flow level assessment was performed using five unlinked polymorphic microsatellite loci. The Bayesian and maximum likelihood analyses revealed a paraphyletic relationship among four old genera (<i>Mauremys</i>, <i>Annamemys</i>, <i>Chinemys</i>, and <i>Ocadia</i>) and suggested the four old genera should be merged into the genus (<i>Mauremys</i>). Ancestral area reconstruction and divergence time estimation suggested Southeast Asia may be the area of origin for the common ancestral species of this genus and genetic drift may have played a decisive role in species divergence due to the isolated event of a glacial age. However, <i>M</i>. <i>japonica</i> may have been speciated due to the creation of the island of Japan. The detection of extensive gene flow suggested no vicariance occurred between Asia and Southeast Asia. Inconsistent results between gene flow assessment and phylogenetic analysis revealed the hybrid origin of <i>M</i>. <i>mutica</i> (Southeast Asian). Here ancestral area reconstruction and interspecific gene flow level assessment were first used to explore species origins and evolution of <i>Mauremys</i> sensu lato, which provided new insights on this genus.</p></div

Phylogenetic trees for <i>Mauremys</i> sensu lato reconstructed based on mt heavy chain 12 protein-coding genes.

<p>Numbers of nearby branches are posterior probabilities (PPs, Left) and bootstrap proportions (BPs, Right) recovered from BI and ML analyses, respectively. Four old genera of <i>Mauremys</i> sensu lato are shown using different colours; i.e., red represents <i>Chinemys</i>; green represents <i>Ocadia</i>; purple represents <i>Mauremys</i>; blue represents <i>Annamemys</i>.</p

Chronogram using BEAST 1.8.0 based on mt heavy chain 12 protein-coding genes.

<p>A. Divergence time estimation; B. The trend of temperature change redrawn from Zachos et al.’s results [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0144711#pone.0144711.ref027" target="_blank">27</a>]. The red zone represents the warming period. The blue zone represents the glacial period.</p

Results for ancestral area reconstruction inferred from BBM and S-DIVA based on mt heavy chain 12 protein-coding genes.

<p>The map is from the Central Intelligence Agency (CIA: <a href="https://www.cia.gov/library/publications/the-world-factbook/index.html" target="_blank">https://www.cia.gov/library/publications/the-world-factbook/index.html</a>). Potential original areas are coded as A: East Asia, B: Southeast Asia and Western Palearctic region (C: West Asia + D: West Europe + E: South Europe and North Africa), shown by different colours in the area pie chart.</p