Josie Lambourdière

The leafy liverwortPorella baueri (Porellaceae) is an allopolyploid

Porella platyphylla andP. cordaeana are genetically well differentiated in Europe (I = 0.486). Isozyme data from 156 European colonies reveal thatP. baueri is polyploid and could be an interspecific hybrid between these two species. It is characterized by large lobe cells, toothed margins of the female bracts, and ciliate perianth mouth. Correspondence analysis using morphological characters revealed that its colonies cluster into two geographicallý separated groups, similar to one or other of the putative parental species. These results agree with the genetic analysis, that also revealed two main allelic associations, each with a distinct geographical range. We hypothesize that this pattern was produced by introgression subsequent to hybridization, or by gene silencing. The discovery of this new, allopolyploid species suggests that hybridization is an important evolutionary process in liverworts.

Barcoding type specimens helps to identify synonyms and an unnamed new species in Eumunida Smith, 1883 (Decapoda:Eumunididae)

TheprimarypurposeofDNA-barcodingprojectsistogenerateanefficientexpertiseandidentificationtool.This is an important challenge to the taxonomy of the 21st century, as the demand increases and the expert capacity does not. However,identifyingspecimensusingDNA-barcodesrequiresapreliminaryanalysistorelatemolecularclusterstoavailable scientific names. Through a case study of the genus Eumunida (Decapoda:Eumunididae), we illustrate how naming molecule-based units, and thus providing an accurate DNA-based identification tool, is facilitated by sequencing type specimens. Using both morphological and unlinked molecular markers (COI and 28S genes), we analysed 230 specimens from 12 geographic areas, covering two-thirds of the known diversity of the genus, including type specimens of 13 species. Most hypotheses of species delimitation are validated, as they correspond to molecular units linked to only one taxonomic name (and vice versa). However, a putative cryptic species is also revealed and three entities previously named as distinct speciesmayinfactbelongtoasingleone,andthusneedtobesynonymised.Ouranalyses,whichintegratethecurrentnaming rules, enhance the a-taxonomy of the genus and provide an effective identification tool based on DNA-barcodes. They illustratetheabilityofDNA-barcodes,especiallywhentypespecimensareincluded,topinpointwhereataxonomicrevision is needed.

Bacterial communities associated with the wood-feeding gastropod Pectinodonta sp. (Patellogastropoda, Mollusca)

Even though their occurrence was reported a long time ago, sunken wood ecosystems at the deep-sea floor have only recently received specific attention. Accumulations of wood fragments in the deep sea create niches for a diverse fauna, but the significance of the wood itself as a food source remains to be evaluated. Pectinodonta sp. is a patellogastropod that exclusively occurs on woody substrates, where individuals excavate deep depressions, and is thus a potential candidate for a wood-eating lifestyle. Several approaches were used on Pectinodonta sampled close to Tongoa island (Vanuatu) to investigate its dietary habits. Host carbon is most likely derived from the wood material based on stable isotopes analyses, and high cellulase activity was measured in the digestive mass. Electron microscopy and FISH revealed the occurrence of two distinct and dense bacterial communities, in the digestive gland and on the gill. Gland-associated 16S rRNA gene bacterial phylotypes, confirmed by in situ hybridization, included members of three divisions (Alpha- and Gammaproteobacteria, Bacteroidetes), and were moderately related (90-96% sequence identity) to polymer-degrading and denitrifying bacteria. Gill-associated phylotypes included representatives of the Delta- and Epsilonproteobacteria. The possible involvement of these two bacterial communities in wood utilization by Pectinodonta sp. is discussed.

Genetic Variation and Population Structure in the Endangered Hermann’s Tortoise: The Roles of Geography and Human-Mediated Processes

The Hermanns tortoise (Testudo hermanni) is an endangered land tortoise distributed in disjoint populations across Mediterranean Europe. We investigated its genetic variation by typing 1 mitochondrial locus and 9 nuclear microsatellites in approximately 300 individuals from 22 localities. Our goal was to understand the relative impact of natural and human-mediated processes in shaping the genetic structure and to identify the genetic priorities for the conservation of this species. We found that 1) all geographic areas are highly differentiated, mainly as a function of their distance but with a clear genetic discontinuity (F st values larger than 0.4) between the Eastern and the Western subspecies; 2) the contact zone between subspecies is located farthest to the west than previously believed, and it probably coincides with the delta of the largest Italian river; 3) extinction events due to climatic conditions in the Upper Palaeolithic and subsequent human-mediated translocations in the Neolithic possibly explain the unexpected similarity among Spain, Sicily, and Corsica. For conservation purposes, the large majority of genetic pools appears native although hybridization among subspecies, related to extensive 20th century trade of tortoises across Europe, is observed in Spain and some Italian samples. Most populations do not seem at immediate risk of low genetic variation, except the French population, which has very low nuclear genetic diversity (heterozygosity = 0.25) and where 50 out of 51 sampled animals shared the same mitochondrial sequence. In general, restocking and reintroduction plans should carefully consider the genetic background of the individuals.

Microsatellite markers for the yam bean Pachyrhizus (Fabaceae)

Premise of the study: Microsatellite loci were developed for the understudied root crop yam bean (Pachyrhizus spp.) to investigate intraspecific diversity and interspecific relationships within the genus Pachyrhizus. Methods and Results: Seventeen nuclear simple sequence repeat (SSR) markers with perfect di- and trinucleotide repeats were developed from 454 pyrosequencing of SSR-enriched genomic libraries. Loci were characterized in P. ahipa and wild and cultivated populations of four closely related species. All loci successfully cross-amplified and showed high levels of polymorphism, with number of alleles ranging from three to 12 and expected heterozygosity ranging from 0.095 to 0.831 across the genus. Conclusions: By enabling rapid assessment of genetic diversity in three native neotropical crops, P. ahipa, P. erosus, and P. tuberosus, and two wild relatives, P. ferrugineus and P. panamensis, these markers will allow exploration of the genetic diversity and evolutionary history of the genus Pachyrhizus.

Genome data on the extinct Bison schoetensacki establish it as a sister species of the extant European bison ( Bison bonasus )

BackgroundThe European bison (Bison bonasus), now found in Europe and the Caucasus, has been proposed to originate either from the extinct steppe/extant American bison lineage or from the extinct Bison schoetensacki lineage. Bison schoetensacki remains are documented in Eurasian Middle Pleistocene sites, but their presence in Upper Pleistocene sites has been questioned. Despite extensive genetic studies carried out on the steppe and European bison, no remains from the fossil record morphologically identified as Bison schoetensacki has been analyzed up to now.ResultsIn this paper, we analyzed a 36,000-year-old Bison schoetensaki bone sample from the Siréjol cave (France) and a cave hyena coprolite (fossilized feces) found in a nearby cave and containing large amounts of Bovinae DNA. We show that the Bovinae mitochondrial DNA sequences from both samples, including a complete mitochondrial genome sequence, belong to a clade recently reported in the literature. This clade only includes ancient bison specimens without taxonomic identification and displays a sister relationship with the extant European bison. The genetic proximity of Bison schoetensacki with specimens from this clade is corroborated by the analysis of nuclear DNA single nucleotide polymorphisms.ConclusionsThis work provides genetic evidence supporting the continuing presence of Bison schoetensacki up to the Upper Pleistocene. Bison schoetensacki turns out to be a sister species of Bison bonasus, excluding the steppe bison Bison priscus as a direct ancestor of the European bison.

Development and characterization of microsatellite markers for Arenaria grandiflora L. (Caryophyllaceae)

Genomic libraries of Arenaria grandiflora enriched for di‐ and trinucleotide repeats were used for the development of novel microsatellite markers. The subset of 13 polymorphic markers was characterized on 40 individuals of A. grandiflora originating from lowland locations in France. The loci amplified 3 to 10 alleles per locus and expected heterozygosities ranged from 0.46 to 0.83. The newly developed markers will be used for population genetic studies and for assessing genetic composition of a restoration experiment of lowland A. grandiflora populations that are protected in France.

Development of microsatellite primers in the protected species Viola elatior (Violaceae) using next-generation sequencing.

Premise of the study: Viola elatior (Violaceae) is a Eurasian perennial plant species in which French populations are threatened by anthropogenic pressures. Microsatellite primers were developed to investigate its genetic structure and diversity. Methods and Results: Eight microsatellite markers were isolated using next-generation sequencing. Loci were amplified and screened for 138 individuals in 17 populations from France. Two of the eight polymorphic loci presented no variability across populations. The total number of alleles per locus varied from two to four. Observed heterozygosity ranged from 0.051 to 1.000. All primers amplified successfully in the closely related species V. pumila. Conclusions: This set of microsatellites offers a valuable tool for assessing population genetic diversity of the species to improve its conservation and base management efforts. High observed heterozygosity values probably reflect the particular mating system of the species and suggest an important tendency to clonality.

Genetic Variation in a North African Rodent Pest, Meriones shawi: Microsatellite Polymorphism

Meriones shawi is an ubiquitous and endemic rodent in northern African. This species is considered as an economically important pest because it often damages crops. Moreover, the gerbillines are known to function as reservoirs for a variety of serious human epidemic diseases. Ten polymorphic microsatellite loci were identified using 454 GS-FLX Titanium pyrosequencing and a multiplex PCR assay was developed. The utility of these markers was evaluated in 30 individuals from three different Moroccan populations. Number of alleles per locus ranged from 2 to 7, with observed and expected heterozygosities ranging from 0.033 to 0.967 and from 0.033 to 0.729, respectively. Departures from Hardy-Weinberg equilibrium were observed at two loci. These markers will be useful resources for future population genetics studies for this rodent and pest-borne disease management.

Phylogeny, biogeography and character evolution in the tribe Desmodieae (Fabaceae: Papilionoideae), with special emphasis on the New Caledonian endemic genera

The nearly cosmopolitan tribe Desmodieae (Fabaceae) includes many important genera for medicine and forage. However, the phylogenetic relationships among the infratribal groups circumscribed using morphological traits are still poorly known. In this study, we used chloroplast (rbcL, psbA-trnH) and nuclear (ITS-1) DNA sequences to investigate the molecular phylogeny and historical biogeography of Desmodieae, and infer ancestral states for several vegetative and reproductive traits. Three groups, corresponding to the Desmodium, Lespedeza, and Phyllodium groups sensu Ohashi were retrieved in the phylogenetic analyses. Conflicts in the topologies inferred from the chloroplast and nuclear datasets were detected. For instance, the Lespedeza clade was sister to the groups Phyllodium+Desmodium based on chloroplast DNA, but nested within the Desmodium group based on ITS-1. Moreover, the New Caledonian endemic genera Arthroclianthus and Nephrodesmus were not monophyletic but together formed a clade, which also included Hanslia and Ohwia based on chloroplast DNA. The hypothetical common ancestor of Desmodieae was dated to the Middle Oligocene (ca. 28.3Ma) and was likely an Asian shrub or tree producing indehiscent loments. Several colonization events towards Oceania, America, and Africa occurred (all less than ca. 17.5Ma), most probably through long distance dispersal. The fruits of Desmodieae repeatedly evolved from indehiscence to dehiscence. We also showed that indehiscent loments allow for more variability in the number of seeds per fruit than indehiscent legumes. Modularity seems here to allow variability in the number of ovules produced in a single ovary.