Une base de données dédiée aux insectes nuisibles rencontrés dans les collections patrimoniales

La base de données "Insectes du patrimoine culturel" recense les espèces d’insectes s’attaquant aux collections muséales sous toutes leurs formes ; elle donne les clés et les différentes procédures pour l’identification de ces insectes afin de limiter leur développement et leur propagation et permettre aux institutions patrimoniales d’envisager des actions curatives et préventives adaptées

A universal DNA mini-barcode for biodiversity analysis

<p>Abstract</p> <p>Background</p> <p>The goal of DNA barcoding is to develop a species-specific sequence library for all eukaryotes. A 650 bp fragment of the cytochrome <it>c </it>oxidase 1 (CO1) gene has been used successfully for species-level identification in several animal groups. It may be difficult in practice, however, to retrieve a 650 bp fragment from archival specimens, (because of DNA degradation) or from environmental samples (where universal primers are needed).</p> <p>Results</p> <p>We used a bioinformatics analysis using all CO1 barcode sequences from GenBank and calculated the probability of having species-specific barcodes for varied size fragments. This analysis established the potential of much smaller fragments, mini-barcodes, for identifying unknown specimens. We then developed a universal primer set for the amplification of mini-barcodes. We further successfully tested the utility of this primer set on a comprehensive set of taxa from all major eukaryotic groups as well as archival specimens.</p> <p>Conclusion</p> <p>In this study we address the important issue of minimum amount of sequence information required for identifying species in DNA barcoding. We establish a novel approach based on a much shorter barcode sequence and demonstrate its effectiveness in archival specimens. This approach will significantly broaden the application of DNA barcoding in biodiversity studies.</p

Alfalfa breeding benefits from genomics of <em>Medicago truncatula</em>

International audienceInternational programs aim at developing knowledge and tools in the model species Medicago truncatula. Genetic resources, DNA sequences, markers, genetic and physical maps are now publicly available. These efforts contribute to improve breeding schemes of crop species such as alfalfa. However, transfer of information from M. truncatula to alfalfa is not straightforward. The article reviews the gain given by the model species to better analyze genetic determinism of breeding traits in alfalfa. It also shows that investments in alfalfa genomics (DNA sequences, SNP development) are needed to benefit from the model species

Alfalfa breeding benefits from genomics of <em>Medicago truncatula</em>

International audienceInternational programs aim at developing knowledge and tools in the model species Medicago truncatula. Genetic resources, DNA sequences, markers, genetic and physical maps are now publicly available. These efforts contribute to improve breeding schemes of crop species such as alfalfa. However, transfer of information from M. truncatula to alfalfa is not straightforward. The article reviews the gain given by the model species to better analyze genetic determinism of breeding traits in alfalfa. It also shows that investments in alfalfa genomics (DNA sequences, SNP development) are needed to benefit from the model species

Role of the <em>RCT1</em> gene in anthracnose resistance in alfalfa

International audienceAnthracnose, caused by Colletotrichum trifolii, is a severe disease of alfalfa (Medicago sativa). The RCT1 gene, isolated from the model legume M. truncatula, is a candidate gene to explain genetic variation for anthracnose resistance in alfalfa. A bulk segregant analysis was carried out to test this hypothesis: from each of eight alfalfa varieties, 15 resistant (R) plants and 15 susceptible (S) plants were selected and DNA was extracted. The whole gene including the upstream and downstream regions (a total of 14 kb) was amplified by PCR for each individual and the R and S plants were pooled for each variety. Sequencing was carried out using the next generation sequencer 454 (Roche). The sequence reads, that averaged 295 bp, were assembled to produce consensus sequences that can be considered as alleles. Considering the five exons of the gene, five regions contained clear deletion/insertion polymorphism but these polymorphisms were present in both the R and S pools. Individual genotyping for these indels indicated that different alleles were present but no specific allele was associated with the phenotype. These polymorphic regions in RCT1 seemed not to explain the variation of anthracnose resistance in alfalfa. However, the presence of one rare allele inducing a lack of function was associated with the resistance. A divergent selection for this allele would test its interest in breeding programs

FIGURES 1 – 4. 1 a in Morphology and DNA barcoding reveal three cryptic species within the Xylophanes neoptolemus and loelia species-groups (Lepidoptera: Sphingidae)

FIGURES 1 – 4. 1 a. Chaerocampa trilineata Walker, [1865], Lectotype, ♂, Venezuela; 1 b. Watercolour of the original type of Sphinx neoptolemus Cramer, 1780; 2 a and 2 b. Xylophanes balcazari n. sp., Holotype, ♂, Mexico, Guerrero; 3 a and 3 b. Sphinx neoptolemus, Neotype, ♂, Venezuela, Aragua; 4 a and 4 b. Xylophanes cthulhu n. sp., Holotype, ♂, Guatemala, Izabal. (2 a, 3 a, 4 a: dorsal view; 2 b, 3 b, 4 b: ventral view)

Molecular identification of Epitrix potato flea beetles (Coleoptera: Chrysomelidae) in Europe and North America

International audienceEpitrix species (Coleoptera: Chrysomelidae) feed mostly on plants from the family Solanaceae and some of them are major pests of potato crops. All Epitrix species are morphologically highly similar, which makes them difficult to identify and limits their study and management. Identification of species is mostly based on the observation of the genitalia and requires a high level of expertise. Here, we propose a tool to reliably identify all developmental stages of the most economically important Epitrix species feeding on potato in Europe and North America (Epitrix cucumeris, Epitrix similaris, Epitrix tuberis, Epitrix subcrinita and Epitrix hirtipennis). We first sequenced two DNA markers (mitochondrial cytochrome c oxidase I (COI) and nuclear internal transcribed spacer 2 (ITS2)) to test their effectiveness in differentiating among six Epitrix species (126 specimens). Morphospecies of Epitrix were well-differentiated by both DNA barcodes and no mitochondrial introgression was detected. Then, we developed an RFLP-based diagnostic method and showed that unambiguous species discrimination can be achieved by using the sole restriction enzyme TaqI on COI polymerase chain reaction products. The tool proposed here should improve our knowledge about Epitrix species biology, distribution and host range, three capacities that are particularly important in the detection and management of these pest species. Specifically, this tool should help prevent the introduction of E. tuberis and E. subcrinita in Europe and limit the spread of the recently introduced E. cucumeris and E. similaris, with minimal disruption to Solanaceae trade

novembre-décembre 2017

Conserver, valoriser et diffuser le patrimoine des musées Les contributions proposées dans ce nouveau numéro de La Lettre de l’Ocim mettent en avant les principales missions des institutions muséales, la conservation-restauration, la valorisation et la diffusion du patrimoine. Ainsi « Transmédia et valorisation du patrimoine : l’exemple de Montaigne Super Star » montre comment la narration transmédia, envisagée comme nouvelle méthode de valorisation et nouvelle pratique de communication, peut être utilisée comme moyen pour repenser la médiation pédagogique. « Boutiques d’établissements culturels : écueils et bonnes pratiques » analyse les différentes stratégies de vente mises en place dans les musées pour permettre au visiteur de prolonger sa visite et au musée de diffuser son image. « Une base de données dédiée aux insectes nuisibles rencontrés dans les collections patrimoniales » décrit Insectes du patrimoine culturel, un outil pour aider les institutions patrimoniales à mener des actions curatives et préventives adaptées. Enfin « Recensement, conservation et valorisation du patrimoine professionnel de la Ville de Paris » présente l’ensemble des actions menées par la Ville de Paris pour insuffler une culture patrimoniale à l’organisation municipale. Serge LOCHOT, rédacteur en che