South Western Pacific map showing the sampling localities of mussels of <i>Idas iwaotakii</i>.

<p>Specimens from Malo and New Caledonia have already been studied by <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0069680#pone.0069680-Lorion1" target="_blank">[7]</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0069680#pone.0069680-Lorion3" target="_blank">[30]</a>.</p

Bayesian tree displaying bacterial symbionts based on the analysis of the 16S rRNA.

<p>Phylotypes associated with <i>I. iwaotakii</i> are shown in bold. Posterior probabilities (PP) and bootstrap values obtained from ML analysis are given above and below branches respectively. PP and bootstrap values lower than 0.90 and 50%, respectively, are not shown. The scale bar represents 0.5% estimated base substitution.</p

Gill filaments of <i>Idas iwaotakii</i>.

<p>(A) TEM view of gill filament of the lateral zone from a specimen of <i>I. iwaotakii</i> collected on wood off Vanuatu. Bacteria (black arrows) are located extracellularly in contact with microvilli. BL: blood lacuna; Lm: basal lamina. (B) Electron micrograph of the extracellular symbionts. Symbiotic bacteria possess a double membrane (white arrow) typical of Gram negative bacteria.</p

Dendrogram obtained from Bayesian analyses of the combined dataset of COI mtDNA and the 28S rRNA.

<p>Asterisks correspond to nodes with posterior probabilities (PP) obtained from BA analysis and bootstrap values obtained from ML analysis that are higher than 0.90 and 50%, respectively. (modified from <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0069680#pone.0069680-Lorion1" target="_blank">[7]</a>).</p

A Remarkable Case of Micro-Endemism in <em>Laonastes aenigmamus</em> (Diatomyidae, Rodentia) Revealed by Nuclear and Mitochondrial DNA Sequence Data

<div><p><em>L. aenigmamus</em> is endemic to the limestone formations of the Khammuan Province (Lao PDR), and is strongly specialized ecologically. From the survey of 137 individuals collected from 38 localities, we studied the phylogeography of this species using one mitochondrial (Cyt b) and two nuclear genes (BFIBR and GHR). Cyt b analyses reveal a strong mtDNA phylogeographical structure: 8 major geographical clades differing by 5–14% sequence divergence were identified, most of them corresponding to distinct karst areas. Nuclear markers display congruent results but with a less genetic structuring. Together, the data strongly suggest an inland insular model for <em>Laonastes</em> population structure. With 8 to 16 evolutionary significant units in a small area (about 200×50 km) this represents an exceptional example of micro-endemism. Our results suggest that <em>L. aenigmamus</em> may represent a complex of species and/or sub-species. The common ancestor of all <em>Laonastes</em> may have been widely distributed within the limestone formations of the Khammuan Province at the end of Miocene/beginning of the Pliocene. Parallel events of karst fragmentation and population isolation would have occurred during the Pleistocene or/and the end of the Pliocene. The limited gene flow detected between populations from different karst blocks restrains the likelihood of survival of <em>Laonastes</em>. This work increases the necessity for a strict protection of this rare animal and its habitat and provides exclusive information, essential to the organization of its protection.</p> </div

Population structure of <i>I. iwaotakii</i>.

<p>Left part: K2P neighbour-joining tree of unique COI haplotypes of <i>I. iwaotakii</i>. The localities at which each haplotype have been sampled is figured by a coloured circle (see legend for correspondence between localities and colours), the number of individuals sharing the same COI haplotype at each locality is given in brackets. The grey rectangles underline the haplotypes shared by the two studied regions. The scale bar represents 0.02% estimated base substitutions. The mitochondrial haplotypes of <i>I. iwaotakii</i> are divided in two clades, A’ and A’’, represented by one panel with large dots and the other one with small dots, respectively. Right part: Median-joining networks (MJN) from COI mtDNA data drawn independently for each of the two studied regions (North Western and South Western haplotypes). Size of haplotype circles is proportional to the number of specimens. Colours used to figure the localities within each region are the same of that used for the NJ tree. A small black circle represents a hypothetical haplotype. The haplotypes shared by the two studied regions are underlined using grey circles over haplotype labels.</p

Geographical localities, substrates, depths and sequences of specimens of <i>I. iwaotakii</i> used in this study.

<p>The number of sequences is indicated in brackets. The superscripts refer to the authors of sequences. The stars indicate the sequences obtained during this study.</p

Mismatch distributions of observed (solid lines) pairwise among-individual comparisons as well as theoretical curves for sudden expansion model (dashed lines)

<p><b>Copyright information:</b></p><p>Taken from "Did glacial advances during the Pleistocene influence differently the demographic histories of benthic and pelagic Antarctic shelf fishes? – Inferences from intraspecific mitochondrial and nuclear DNA sequence diversity"</p><p>http://www.biomedcentral.com/1471-2148/7/220</p><p>BMC Evolutionary Biology 2007;7():220-220.</p><p>Published online 12 Nov 2007</p><p>PMCID:PMC2222253.</p><p></p> For each species, the mismatch distribution of cyt b sequences is given on the left side, while the mismatch distribution of the S7 sequences is given at the right

Semi-thin sections of the digestive tract of <i>Idas iwaotakii</i>.

<p>The specimen was collected on turtle bone off New Caledonia. (A) Overall view of the digestive tract (longitudinal sections). The black arrow indicates the location of microvilli in the intestine. (B) Cross section of the oesophagus lined by a stratified epithelium. (C) Cross section of the intestine. (D) Cross section of the stomach lined by a cuboidal epithelium. The white arrow indicates the gastric shield. (E) Longitudinal section of a detail of intestinal contents.</p

Minimum spanning networks of <i>L. aenigmamus</i> nDNA haplotypes (BFIBR, GHR and BFIBR+GHR combined).

<p>Circle sizes are proportional to the number of similar haplotypes observed in the data set. Branch lengths are proportional to the number of mutations between haplotypes. Colors refer to each clade or subclade identified in the phylogenetic analysis. Missing haplotypes are represented by a white square.</p