Participatory Plant Breeding for Organic Farming in France, the cauliflower experience at the PAIS

The availability of organic seeds is a great problem for organic farmers. The private sector of plant breeding meets difficulties to answer to the organic farming (OF) demand, characterized by small quantities and a great diversity of criteria and by breeding methods which respect the natural species characteristics (see IFOAM Draft Standard on organic seeds and plant breeding). So, the organic sector is organizing breeding and seed production by itself In France, since 2001, a Brittany regional organic umbrella (IBB, Inter Bio Bretagne), and some researchers from the national institute for agronomical research (INRA) have initiated a breeding program for organic production and a participatory plant breeding (PPB) program for organic cabbages and cauliflowers in Brittany, from the evaluation of genetic resources of several European gene Banks. In the PPB, the farmers are taking in charge breeding and seed production of open pollinated varieties. Several types were kept and bred, depending on the way of production and commercialization for each farmer. In the northern Brittany, farmers have not forgotten the traditional production of cauliflower seeds. PAIS, the agrobiological experimental station of IBB on the organic site of an agricultural school (Suscinio, Morlaix), is the meeting point for all the involved actors (farmers, traders, trainers, researchers…). There, the farmers and traders can find technical and scientific information, and they can share their experiences from the plant selection to seed production. Today, other French PPB initiatives involve several species and organic farmers groups, to promote biodiversity and a best adaptation to a local production: durum wheat in the Mediterranean area, bread wheat with the “paysan-boulangers”, maize and sunflower in the South-West of the country, tomato in the South-East, radishes, parsnip and summer cauliflower, in Pays de Loire. From these experiences, the PPB for organic farming consists in the constitution of the organic farmers group with the creation of exchange space for researchers and others organic actors, the definition of the priority in matters of crops, the discovering and selection of genetic resources in the farmers fields, the exchange of experiences and genetic resources through formal and informal, regional, national or international, farmer and organic professional meetings (accompanied by researchers and often enlarged to gardeners and trainers). The seed distribution has been depending on the French legislative evolution. By nature, the varieties issued from PPB could not fill the DUS (Distinction, Uniformity, Stability) characteristics for registration. And mainly, by ethics, the organic way of development should enhance the ancestral link between the plant and the farmers, link which needs exchanges to allow the evolution of the crops and the conservation of a living biodiversity

Direct interaction of TrkA/CD44v3 is essential for NGF-promoted aggressiveness of breast cancer cells

Background CD44 is a multifunctional membrane glycoprotein. Through its heparan sulfate chain, CD44 presents growth factors to their receptors. We have shown that CD44 and Tropomyosin kinase A (TrkA) form a complex following nerve growth factor (NGF) induction. Our study aimed to understand how CD44 and TrkA interact and the consequences of inhibiting this interaction regarding the pro-tumoral effect of NGF in breast cancer. Methods After determining which CD44 isoforms (variants) are involved in forming the TrkA/CD44 complex using proximity ligation assays, we investigated the molecular determinants of this interaction. By molecular modeling, we isolated the amino acids involved and confirmed their involvement using mutations. A CD44v3 mimetic peptide was then synthesized to block the TrkA/CD44v3 interaction. The effects of this peptide on the growth, migration and invasion of xenografted triple-negative breast cancer cells were assessed. Finally, we investigated the correlations between the expression of the TrkA/CD44v3 complex in tumors and histo-pronostic parameters. Results We demonstrated that isoform v3 (CD44v3), but not v6, binds to TrkA in response to NGF stimulation. The final 10 amino acids of exon v3 and the TrkA H112 residue are necessary for the association of CD44v3 with TrkA. Functionally, the CD44v3 mimetic peptide impairs not only NGF-induced RhoA activation, clonogenicity, and migration/invasion of breast cancer cells in vitro but also tumor growth and metastasis in a xenograft mouse model. We also detected TrkA/CD44v3 only in cancerous cells, not in normal adjacent tissues. Conclusion Collectively, our results suggest that blocking the CD44v3/TrkA interaction can be a new therapeutic option for triple-negative breast cancers

PCBs and DDTs in Stenella coeruleoalba dolphins from the French Mediterranean coastal environment (2007-2009): Current state of contamination

International audienceOrganochlorinated compounds including PolyChloroBiphenyles, Dichloro-DiphenylTrichloroethan and metabolites are determinated in Stenella coeruleoalba (n = 37) stranded on the french Mediterranean coasts from 2007 till 2009. Studies are carried out on lung, muscle, kidney, liver, and blubber. The sought-after compounds are all detected to variable levels in each tissue and organ. In general, total PCBs are the most abondant, followed by total DDTs. The concentration (in ng g(-1) of lipid weight) in blubber of S. coeruleoalba, varied from 2,052 to 158,992 for PCBs and from 1,120 to 45,779 for DDTs. The ratios DDE/tDDTs are higher than 80% in almost all samples. The overall results of this work, compared to previous studies concerning the Mediterranean Sea, seems to confirm the tendency to a decrease of the contamination by organics compounds for the cetaceans in the Western Mediterranean Sea. (C) 2012 Elsevier Ltd. All rights reserved

Atmospheric input of inorganic nitrogen and phosphorus to the Ligurian SEA: Data from the cap Ferrat coastal time-series station

International audienceAtmospheric fluxes of bio-available inorganic nitrogen (DIN, i.e. nitrate+ammonium) and phosphorus (DIP, i.e. phosphate) were measured in 2010, 2011 and 2013 at the sampling station of Cap Ferrat (Ligurian Sea). Wet and dry fluxes of DIN, averaged over three years, were 35 and 19 mmol m−2 yr−1, respectively. Most of the nitrate was deposited under dry form, whilst ammonia was twice more found in wet deposition. Wet and dry fluxes of DIP, averaged over three years, were 0.11 and 0.64 mmol m−2 yr-1, respectively. Atmospheric fluxes of DIN and DIP were compared with other photic zone nutrient input sources, physical and biological, i.e. winter convection, N2 fixation, and upward diffusion. Even if convection is by far the most important nutrient input for surface waters, atmospheric sources may be the second one, supplying more nutrients than diazotrophy and diffusion, particularly in conditions of water column stratification

Tritium and 14C dependencies upon particulate organic matter within the nuclearized Rhone River (France)

International audiencePurpose Radiocarbon and tritium are the dominant radionuclides released by nuclear industries over the world. Close interactions of these elements with particulate organic matter (POM) in soils and rivers are widely reported in the literature but only few studies focus on their relationships with POM within nuclearized rivers. Here, we focus on the nuclearized Rhone River (France) and its tributaries in order to highlight the behavior of these two radionuclides owing to POM amounts and nature . Materials and methods Over the 2001-2021 period, suspended sediments (TSS) samples were acquired and analyzed thanks to the MOOSE network (Mediterranean Ocean Observing System for the Environment) and of the Rhone Sediment Observatory. Over this period, TSS, particulate organic carbon (POC), dissolved organic carbon (DOC), and chlorophyll and phaeopigment contents were determined at the SORA monitoring station located at the downstream part of the Rhone River. These parameters were measured from daily to weekly after continuous filtration of the waters collected from high-frequency water samplings. Larger amounts of TSS were also collected by using time integrating particle traps (PT) at the SORA station and on several Rhone tributaries. These latter samples were analyzed for global biogeochemistry (Rock Eval 6), organically bound tritium (OBT), and radiocarbon. Results and discussion At the downstream part of the Rhone River, POC represents from 1 to 10 wt.% of the TSS even though this amount rises to 20 wt.% very occasionally. POC/TSS shows a positive relationship with the chlorophyll/phaeopigment amounts reinforcing the non-negligible production of autochthonous POM in this river. The increase of C-14 contents and Delta C-14 signatures with the amount of aquatic POM underlines that a significant part of C-14 from industrial releases is transported as fresh and labile particulate organic compounds. In tributaries, Delta C-14 signatures decrease with the rising amounts of C-14 depleted refractory carbon (RC/TOC) coming from soil erosion in a similar way. OBT contents show no relationships with neither the contents nor the nature of naturally occurring POM. Conclusions Autochthonous POM would constitute a key route to transfer radiocarbon from nuclear releases towards the food chain. Normalizing radiocarbon contents with RC/POC constitutes a new powerful tool to better assess the environmental labelling of radiocarbon discharged by the nuclear industries as the dilution effect generated by dead carbon is discarded. In the Rhone River, OBT is mostly associated with synthesized organic particles inherited from watch industries

Culture légumière biologique: le défi variétal. Exemple des choux et choux-fleurs bio en Bretagne

Supplément : Le MaraîcherNational audienc

Evaluation of pollutant exposure by chemical and biological markers in a Mediterranean French urban stream: A step for in situ calibration of multixenobiotic resistance transporter expression as biomarker in Chironomidae larvae

International audienceThis study was aimed at semi-quantifying the membrane density of multixenobiotic resistance (MXR) transporters in Chironomidae Orthocladiinae larvae from an urban stream by ELISA assay. The relationships between the MXR transporter membrane density and limnological parameters and pollutant concentrations, 16 priority polycyclic aromatic hydrocarbons (PAHs), as per the US Environmental Protection Agency (EPA) and seven polychlorobiphenyl congeners (PCBs), were assessed. Midge larvae were collected, and limnological parameters and pollutant concentrations were measured in three sites of a French Mediterranean urban stream, two located after sewage treatment plants, and one closed to the river mouth, and in two additional sites, one on the stream tributary, and one in a non-urbanized stream located in the same region. Results show that the PAH and PCB contamination levels are different between sites and that some congener concentrations are above their threshold toxic effect level (TEL). The MXR transporter membrane density was significantly higher in larvae from the tributary, the most polluted site, as compared with larvae from the non-urbanized stream. The MXR transporter density was positively correlated with 10 of the 16 US-EPA PAH concentrations and the increase in the MXR transporter density seems to be due to the US-EPA PAH concentrations that were above their TEL. No relations with PCB concentrations or limnological parameters were found. The results suggest that the MXR transporter membrane density in Chironomidae larvae could be an interesting biological marker of PAH exposure in freshwater ecosystems

The contrasting genetic patterns of two sympatric flying fox species from the Comoros and the implications for conservation

International audiencePteropus livingstonii and Pteropus seychellensis comorensis are endemic fruit bat species that are among the most threatened animals in the Comoros archipelago. Both species are pollinators and seed dispersers of native and cultivated plants and are thus of crucial importance for the regeneration of natural forests as well as for cultivated plantations. However, these species are subject to strong anthropogenic pressures and face one of the highest rates of natural habitat loss reported worldwide. Yet little is known about the population genetic structure of these two species, making it difficult to define relevant conservation strategies. In this study, we investigated for the two flying fox species (1) the level of genetic diversity within islands, as well as across the archipelago and (2) the genetic structure between the two islands (Anjouan and Moheli) for P. livingstonii and between the four islands of the archipelago (Anjouan, Moheli, Grande Comore and Mayotte) for P. s. comorensis using mitochondrial and microsatellite markers. The results revealed contrasting patterns of genetic structure, with P. s. comorensis showing low genetic structure between islands, whereas P. livingstonii exhibited high levels of inter-island genetic differentiation. Overall, the genetic analyses showed low genetic diversity for both species. These contrasting genetic patterns may be the result of different dispersal patterns and the populations' evolutionary histories. Our findings lead us to suggest that in terms of conservation strategy, the two populations of P. livingstonii (on Anjouan and Moheli islands) should be considered as two separate management units. We recommend focusing conservation efforts on the Anjouan population, which is the largest, exhibits the highest genetic diversity, and suffers the greatest anthropogenic pressure. As for P. s. comorensis, its four populations could be considered as a single unit for conservation management purposes. For this species, we recommend protecting roosting trees to reduce population disturbance

Calpain 2-dependent IκBα degradation mediates CPT-11 secondary resistance in colorectal cancer xenografts

International audienceCPT-11 (irinotecan), the first-line chemotherapy for advanced stage colorectal cancer, remains inactive in about half of patients (primary chemoresistance) and almost all initial responders develop secondary resistance after several courses of treatment (8 months on average). Nude mice bearing HT-29 colon cancer xenografts were treated with CPT-11 and/or an NF-κB inhibitor for two courses. We confirm that NF-κB inhibition potentiated CPT-11 anti-tumoural effect after the first course of treatment. However, tumours grew again at the end of the second course of treatment, generating resistant tumours. We observed an increase in the basal NF-κB activation in resistant tumours and in two resistant sublines, either obtained from resistant HT-29 tumours (HT-29R cells) or generated in vitro (RSN cells). The decrease of NF-κB activation in HT-29R and RSN cells by stable transfections with the super-repressor form of IκBα augmented their sensitivity to CPT-11. Comparing gene expression profiles of HT-29 and HT-29R cells, we identified the S100A10/Annexin A2 complex and calpain 2 as over-expressed potential NF-κB inducers. SiRNA silencing of calpain 2 but not of S100A10 and/or annexin A2, resulted in a decrease in NF-κB activation, an increase in cellular levels of IκBα and a partial restoration of the CPT-11 sensitivity in both HT-29R and RSN cells, suggesting that calpain 2-dependent IκBα degradation mediates CPT-11 secondary resistance. Thus, targeted therapies directed against calpain 2 may represent a novel strategy to enhance the anti-cancer efficacy of CPT-11.</p