Southeast France Research Articles

Groundwater-surface water exchanges in an alluvial plain in southern France subjected to pumping: A coupled multitracer and modeling approach

Study regionThe study was conducted in an alluvial plain between the Rhône and the Ouvèze Rivers (in the southeast of France) extensively exploited for drinking water. The research area is characterized by significant groundwater-surface interactions influenced by groundwater pumping activities. Study focusThe aim of this study is to enhance the understanding of interactions between rivers and alluvial aquifers by combined multi-tracer and numerical modeling approaches. Over an 18-month period, groundwater temperature, piezometric levels, and river surface water levels were continuously monitored. Field campaigns focused on conductivity, stable isotopes of water, and radon-222 activity concentration in both groundwater and surface water. Radon-222 was used to quantify water exchanges between the river and the aquifer. A MODFLOW model, calibrated using piezometric data and PEST, was employed to simulate groundwater flow and reactive transport of radon-222 using MT3DMS. New hydrological insights for the regionThe study reveals that river water recharges the aquifer, with radon-222 data delineating this recharge zone. The methodology extended the interpretation of periodic groundwater temperature signals to isotopic signals, allowing the identification of dispersivity and Darcy's velocity. The Ouvèze River was found to contribute approximately 55 % of the pumping water supply, alongside the Rhône. These findings provide valuable insights for sustainable water resource management, demonstrating the relevance of using natural tracers in scenarios where artificial tracers are impractical.

Determination of atmospheric circulation patterns causing high temperatures in the South-East of France between June and September: case of the Côte d'Azur

Determination of atmospheric circulation patterns causing high temperatures in the South-East of France between June and September: case of the Côte d'Azur

Analyzing the impacts of climate change on ecosystem services provided by apple orchards in Southeast France using a process-based model

We know that fruit production, especially in the Mediterranean, will need to adapt to climate change to ensure the sustainability of fruit tree-based agroecosystems. However, there is a lack of evidence on the long-term effects of this change on sustainability indicators. To fill this gap, we used a fruit tree model, QualiTree, to analyze the impacts ofclimate change on the ecosystem services provided by apple orchards in south-eastern France. To do this, a blooming model was parameterized to simulate blooming date on the basis of climate data, and QualiTree was supplemented with a model of nitrogen processes in the tree and a soil module describing resource input (irrigation, mineral and organic fertilization), transfer in the soil (water and nitrogen) and metabolic transformation-immobilization (mineralization, (de)nitrification). This type of extension makes it possible to simulate a wide array of ecosystem services, including C sequestration, nitrate leaching and nitrous oxide emissions. The model was compared with data from an apple orchard in southeastern France. The predicted daily mean and variability over time of fruit growth, composition and soil water content were consistent with observed data. QualiTree was then used to assess the potential impacts of climate change on the ecosystem services supplied by apple orchards. For this purpose, weather variables from 2020 to 2100 were generated for three contrasted greenhouse gas emission scenarios, and simulations were performed under two irrigation schemes (no restriction and restricted use of water). Model outputs indicated that, on average, marketable apple yields would increase until 2050 and then subsequently decrease. The fruit refractometric index, an indicator of fruit quality, was projected to sharply decrease with the intensity of climate change. Ecosystem services such as C sequestration by the orchard will decrease with climate change severity, mainly due to a higher mineralization of soil humus, whereas N2O emissions will increase with larger denitrification rates. Soil water availability, fertility, drainage and leaching were predicted to depend more on the irrigation strategy than on climate change severity. The new functions performed in QualiTree broadened its predictive capabilities and allowed for a better understanding of ecosystem service delivery in fruit orchards under varying climate conditions.

Biostratigraphic implications of the Valanginian to Lower Hauterivian benthic foraminifers from the Vergol/La Charce composite Section (southeast France, Vocontian Basin)

The well-exposed Valanginian to Lower Hauterivian sequences of the Vocontian Basin (South-East France) are revisited based on a micropalaeontological study of material collected in the Vergol and La Charce sections. A total of 528 tests of benthic foraminifers were recorded in good state of preservation. A biometric analysis of the species Dorothia hauteriviana is proposed in order to identify its morphotypes and their biostratigraphic significance. This study aims to identify benthic foraminiferal assemblages and to propose an integrated biostratigraphy along the Valanginian to Hauterivian sequence of the Vergol and La Charce sections (Vocontian Basin). Two foraminiferal assemblages have been recognized. The Lenticulina nodosa foraminiferal assemblage ranges from the lower Valanginian to the basis of the upper Valanginian Saynoceras verrucosum ammonite standard zones (StZ). The Lenticulina busnardoi foraminiferal assemblage is recorded from the second half of S. verrucosum to the top of Neocomites peregrinus StZ. The current study shows that the Vergol and La Charce composite section represents a complete segment of Valanginian to Lower Hauterivian foraminiferal assemblages, and records several changes in taxonomic biodiversity and dynamics of population for this interval.

Sedimentology and structure of the Paleogene Nummulitic series of Corsica: Reconstruction of the southern termination of the western Alpine foreland basin

AbstractNummulitic Limestones deposits are preserved along the tectonic contact between the Variscan basement and Alpine units of Corsica. These marine carbonates, dated from the Late Palaeocene to the Middle Eocene, were deposited within a foreland flexural basin that is considered to be the southern continuation of the Alpine foreland basin of southeast (SE) France. However, in contrast with the Nummulitic Limestones of SE France, those of Corsica are far less documented. This field‐based study constrains the sedimentology, stratigraphy and structure of the Nummulitic Limestones of Corsica in three localities (Balagne, Corte and Sari‐Solenzara) to identify factors that controlled foreland basin development and to clarify its significance within the early alpine orogen. The microfacies, microfaunal assemblages and siliciclastic fractions are characterised throughout the succession at each locality. The results indicate the existence of an important Variscan basement relief to the west of the basin (West Corsican Massif) that supplied early alluvial fans found at the base of the foreland succession in the northernmost Balagne area. Continuous high clastic input strongly reduced the development and diversity of the overlying Nummulitic Limestones facies and fauna. Further south, limestones in the Corte and Sari‐Solenzara areas are thicker and contain richer fauna. Three depositional models corresponding to the carbonate ramp system are proposed for the Nummulitic Limestones and used to construct paleogeographic maps illustrating the transgressive evolution of the Corsican foreland basin from the Early to the Late Eocene. Based on our results and available regional tectonic data and LT thermochronological data, we propose that the Nummulitic marine transgression took place within a continuous foreland basin encompassing southern Corsica and SE France during the early development of the western alpine arc.

Application of non-stationary shear-wave velocity randomization approach to predict 1D seismic site response and its variability at two downhole array recordings

Accounting for uncertainties in seismic site response is crucial to improving the performance of one-dimensional (1D) ground response analyses (GRAs) at downhole array recording sites. In addition to site effects, uncertainties in 1D-GRAs can also be contributed from the seismic source and/or path. Though often representing not more than one percent of the distance (path) from the source, site conditions are known to have an enormous influence on ground shaking. In this study, we focus on the site shear-wave velocity (VS) structure, which is the main ingredient for estimating the variability of site response. As such, VS can manifest aleatory uncertainties related to the effects of small-scale spatial heterogeneities within the near surface, thus VS can substantially modify ground shaking during earthquakes. We apply a novel VS randomization approach to propagate the small-scale heterogeneities of VS to estimate seismic site response within a non-stationary probabilistic framework. The randomization approach generates samples of VS profiles that are used to perform several 1D-GRAs and obtain an averaged site response and related variability. The proposed method is implemented on data recorded at two downhole array sites with different subsurface soil conditions: a soft soil site on Treasure Island (California, United States of America) and a rock outcrop site in Cadarache (South-East France). We show that synthetic surface-to-borehole transfer functions from 1D-GRAs provide an acceptable fit to the empirical transfer functions from low-motion earthquake records and succeed in reproducing most of the site-specific seismic response variability. The remaining mismatch between transfer functions is likely due to insufficient precision on the seismic bedrock and the impedance contrast. The variability in site response is discussed with emphasis on the role of VS small-scale heterogeneities, attenuation, and input motion incidence angle in ground motion variability for the site and soil conditions at both locations.

Site Settlement Patterns During MIS 3 in the Southeast of France: the Lithic Assemblages of Two Phases of Occupation (Levels 4.1 and 4.2) at the Abri du Maras

Site Settlement Patterns During MIS 3 in the Southeast of France: the Lithic Assemblages of Two Phases of Occupation (Levels 4.1 and 4.2) at the Abri du Maras

Investigating transmission patterns among preterm neonates during an outbreak of necrotizing enterocolitis related to Clostridium butyricum using whole-genome sequencing

BackgroundNecrotizing enterocolitis is the most severe life-threatening acquired gastrointestinal disorder among preterm neonates. We describe here an outbreak of Clostridium butyricum-related necrotizing enterocolitis in preterm neonates that occurred in three different neonatal centres, in southeast France. MethodsWe defined a confirmed case of C. butyricum-related necrotizing enterocolitis in preterm neonates by the presence of clinical signs according to modified Bell criteria and C. butyricum identified from stools sample using real-time polymerase chain reaction or culture. A phylogenetic analysis of the isolated strains by whole genome sequencing was also performed. ResultsBetween 5 and 27 January 2022, we identified ten confirmed cases of C. butyricum-related necrotizing enterocolitis, including five from neonatal centre 1, four from neonatal centre 2, and one from neonatal centre 3. The attack rate of necrotizing enterocolitis in neonatal centre 1 was 7.1% (5/70). The positivity rate of C. butyricum detected from stool samples was higher during the outbreak period (37/276; 13.4%) than outside this period (7/369; 1.9%), while systematic screening was maintained (P<0.001). Phylogenetic analysis showed a clonality between strains inside four clusters. Two clusters included neonates hospitalised in different neonatal centres, suggesting the transmission of C. butyricum strains during the transfer of neonates between neonatal centres. ConclusionsThis outbreak of C. butyricum-related necrotizing enterocolitis confirms a cross-transmission between preterm neonates, including twin or triplet siblings, and involving necrotizing enterocolitis cases together with asymptomatic carriers. After three months of follow-up, no further cases were identified following the implementation of contact precautions with sporicidal agents.

Impact of agroecological practices on Phytoseiidae communities in a vineyard of South of France: effect of covercrops and agroforestry.

Viticulture is characterized by substantial pesticide applications, impacting natural enemies. New pest control strategies and management of plant diversity into agrosystems acting as reservoirs of natural enemies are assumed to limit pesticide use. Various studies support this hypothesis but gaps exist on the effect of diversification on Phytoseiidae mites, generalist predators reported as prevalent and efficient natural enemies in vineyards. This study focuses on the effect of cover crop management (no cover crop, spontaneous cover crops with or without agroforestry) and grape variety (resistant cv. Artaban and cv. Syrah) on predatory mites and prey communities, in a newly planted experimental vineyard in South-East France. Samplings were carried out three times a year on vine, cover crops, and co-planted trees. Phytoseiidae, Tydeiidae, Eriophyidae mites and thrips were characterized. Nine Phytoseiidae species were identified on vine, the main ones being Kampimodromus aberrans, Typhlodromus exhilaratus, Phytoseius finitimus and Euseius gallicus. Kampimodromus aberrans was prevalent on the cv. Syrah, highlighting a strong effect of variety. The low unexpected effect of system management observed outcome could be due to several factors, such as the experimental plot size or the influence of vine stress on Phytoseiidae communities in vines with cover crops. All phytoseiid species present on vine were identifed at least once on cover crops and co-planted trees, suggesting their potential role as reservoirs. Further studies should be performed investigating the evolution of communities in this newly-planted experimental system, as well as potential differences in trophic network interactions.

Seasonal Effects on Health Status and Parasitological Traits of an Invasive Minnow in Iberian Waters.

Biological invasions are of special conservation concern in the Iberian Peninsula and other regions with high levels of endemism. Environmental variability, such as the seasonal fluctuations of Mediterranean streams, is a key factor that affects the spread of aquatic species in novel habitats. Fish parasites have a great potential to reflect such changes in the habitat features of freshwater ecosystems. The aim of this study consisted of seasonally analysing the health status and parasitological traits of non-native fish in Iberian waters. In particular, a strongly invasive population of Languedoc minnow Phoxinus septimaniae (leuciscid species native to south-east France) was assessed in Tordera Stream (north-eastern Iberian Peninsula, Mediterranean conditions). Fish were sampled in April, July, and October 2023 by electrofishing. Health status (external/internal organs) was significantly better in autumn (HAI = 28.8) than spring (HAI = 35.6). Life-cycle complexity was higher in spring (LCI = 1.98), whereas parasite abundance and Shannon diversity were significantly lower in autumn (TA = 19.6 and H' = 2.15, respectively). In October (more 'benign' environmental conditions in Iberian streams), minnows could display elevated foraging activity, with fish increasing their health condition and level of parasite resistance/tolerance. Overall results showed a particular seasonal profile of health and parasite infra-communities that allow this minnow species to thrive under highly fluctuating habitat conditions. This information could help environmental managers to control non-native fish in Mediterranean streams.

Asymptomatic Leishmania infantum infection in dogs and dog owners in an endemic area in southeast France.

The prevalence of asymptomatic leishmaniasis in dogs and their owners in the main endemic areas of France has not been studied to date. The objective of this study was to quantify asymptomatic Leishmania infantum infection in southeast France in healthy people and their dogs using molecular and serological screening techniques. We examined the presence of parasitic DNA using specific PCR targeting kinetoplast DNA (kDNA) and specific antibodies by serology (ELISA for dogs and Western blot for humans) among immunocompetent residents and their dogs in the Alpes-Maritimes. Results from 343 humans and 607 dogs were included. 46.9% (n=161/343) of humans and 18.3% (n=111/607) of dogs were PCR positive; 40.2% of humans (n=138/343) and 9.9% of dogs (n=60/607) were serology positive. Altogether, 66.2% of humans (n=227) and 25.7% of dogs (n=156) had positive serologies and/or positive PCR test results. Short-haired dogs were more frequently infected (71.8%, n=112) than long-haired dogs (12.2%, n=19) (p=0.043). Dogs seemed to be more susceptible to asymptomatic infection according to their breed types (higher infection rates in scenthounds, gun dogs and herding dogs) (p=0.04). The highest proportion of dogs and human asymptomatic infections was found in the Vence Region, corresponding to 28.2% (n=20/71) of dogs and 70.5% (n=31/44) of humans (4.5/100,000 people). In conclusion, the percentage of infections in asymptomatic humans is higher than in asymptomatic dogs in the studied endemic area. It is questionable whether asymptomatic infection in humans constitutes a risk factor for dogs.

Dating the late Miocene marine sediments around the southern middle Durance valley (Provence, SE France): new evidences for a Tortonian age

The present study aims dating the topmost 50 m of a 115 m-long core retrieved from a valley located in the Cadarache Area (Upper Provence, South East France). Based on burial dating by in situ produced cosmogenic nuclides (10Be, 26Al and 21Ne), and paleomagnetic analyses, a Tortonian age was determined for the sedimentary succession exhibited in the core. In addition, thin sections, grain size analyses and quartz morphoscopy were used to characterize a shallow marine environment and to correlate the sediment core to the surrounding exposed sections. When comparing the studied sedimentary record to global sea level estimates, we establish that the local Tortonian transgression was not synchronous with the global scale sea level high-stand, but happened more likely later, during a global regressive trend. The timing of the Tortonian flooding in Upper Provence was therefore most probably driven by regional tectonic forcing. Finally, the Tortonian shallow marine sediments are topped by lacustrine tight carbonates. These carbonates protect the marine sediments from the following major erosional events resulting from the Messinian sea level drop and from interglacial-glacial fluctuations that both yielded to the present-day valley topography.

A Late Neolithic Structured Dwelling: the Automobile Village of Lachaup, Gap (Hautes-Alpes) (Abridged version)

The Village Automobile de Lachaup, located about 5 km south of Gap agglomeration, was the subject of a preventive excavation in 2015 executed by Inrap under the direction of D. Dubesset. The site is located on the western slope of a small relief culminating at about 720 m altitude. The study revealed a structured habitat articulated around a ditch. To the east, it delimits an area devoted to the installation and operation of twenty circular heating stone hearths. Organic analyzes realised on the blocks of four hearths made it possible to highlight contact with animal fat and thus confirm their functioning in a culinary context. The domestic space is located west and below the ditch and more precisely in the northwestern part of the excavated right-of-way. In this sector, a house plan of approximately 104 m² was highlighted. The building consists of eighteen post holes. They draw a symmetrical rectangular plan with two naves. The associated domestic space is made up of floor revealed through a micromorphological study, a small hearth with hot stones and other postholes. The small amount of finds collected provides little information. Thus, the chronology was apprehended through the nine radiocarbon analyses. After calibration, these give an overall chronological range between 2886 and 2468 cal. BCE at 95.40% probability. The imprecision can be explained by a plateau phenomenon. The site of the Lachaup automobile village is singular because of the organization of its space. It renews our knowledge of habitat in the South-East of France and allows us to understand in a new light the ways of life of late Neolithic societies in the Hautes-Alpes.

Messinian canyons morphology of the Rhône and Ardèche rivers (south-east France): new insights from seismic profiles

Twelve available two-way time high-resolution seismic reflection profiles located in the central part of the middle Rhône valley are interpreted. In addition, one of the profiles was reprocessed to determine the P-wave velocities of the main geological units and to convert this profile into a depth cross section. The Lower and Upper Cretaceous units are clearly identifiable on all the profiles, along with the Messinian Erosion Surface (MES) carved out during the Messinian Salinity Crisis (MSC) by the paleo-Rhône and its western tributaries, the Ardèche and Cèze paleo-canyons. The Plio-Quaternary fill of these paleo-canyons shows at least 4 main units with an overall transgression. The combination of geological data from geological maps, geological field surveys and borehole data made it possible to model the MES in 3D at the scale of the region, and to produce depth/elevation model. From a geological point of view, the interpretation of the seismic profiles enabled us to reconstruct the stages in the sub-aquatic filling of the Messinian-Pliocene aggradation of the paleo-river. Several Mass Transport Deposits (MTDs) were identified both during the drop and during the rise in the Mediterranean Sea level. From a geomorphological point of view, this study provides new insights in the route and longitudinal profile of paleo-rivers and, in particular, it deepens the profile of the Paleo-Rhône at the latitude of the Tricastin region (up to −700 m b.s.l.) and significantly modifies the course and depth of the Ardèche proposed in previous studies. The N-Ardèche river, known to develop a karstic system during the MSC, is connected to a deep canyon, most likely through a karstic pocket valley, as suggested by the very steep longitudinal profile of the MES. Finally, from a structural point of view, our interpretation of the seismic profiles shows a broad ENE-trending anticline structure associated with a normal fault which apparently did not affect the Mio-Pliocene fill. In the southern part of the area, near the Uchaux anticline, the imaged structures suggest the presence of a recent (syn- to post-Pliocene) fault propagation fold. In addition to all the new information on the geology, morphology and methods of excavation and filling of the Messinian paleo-canyon, the proposed topographic model of the paleo-canyon is crucial for modelling seismic movement in the context of a basin with a complex geometry and, in particular, for the numerical assessment of site effects in a context of low seismicity.

Melitta seitzi Alfken, 1927, une nouvelle mélitte pour la faune française (Hymenoptera, Melittidae)

Melitta seitzi Alfken, 1927, a new melittid bee to the French fauna (Hymenoptera, Melittidae). Melitta seitzi (Melittidae), a bee species previously known only in Spain, was found in 2022 in southeast France as part of a project to improve knowledge of wild pollinators in the Parc Naturel Régional du Verdon. Additional surveys carried out in 2023 revealed that the females forage locally on the flowers of Lotus dorycnium L. (Fabaceae). An analysis of the bee assemblages observed at the same time as M. seitzi leads us to suspect a possible association of M. seitzi with some cuckoo-bees of the genus Nomada. The article also proposes an identification key to distinguish M. seitzi from the other species of the genus present in France. This key is accompanied by a comparative table.

Continental depositional record of climate and tectonic evolution around the Eocene-Oligocene transition in southeast France: perpectives from the Vistrenque Basin (Camargue)

Based on detailed sedimentological analyses of cores, interpretation of well logs and a set of geochemical measurements performed on lacustrine sedimentary rocks, the palaeoenvironmental evolution and the sedimentary architecture of the Paleogene continental Vistrenque Basin (SE France) have been reconstructed. The analysis of sedimentary archives revealed three main stages of basin infill evolution: (1) a deep-lake basin (Priabonian-earliest Rupelian) whose sedimentation was dominated by terrigenous gravity-driven deposits during a period of high subsidence rate and strike-slip fault activity and under a prevailing humid climate; (2) an evaporative deep lake (early Rupelian) characterized by a drastic reduction in lake volume (forced-regression), terrigenous supplies and deposition of evaporites in disconnected sub-basins; (3) an overall long-term normal regressive stage (middle Rupelian to earliest Chattian) of lake infill characterized by an increase in terrigenous supplies and a vertical upward transition from deep-lake gravity-driven deposits to marginal lake and floodplain sedimentation. The onset of lake volume reduction and forced regression during the early Rupelian is associated with (1) the reworking of marginal lake carbonates into the deep lake areas, (2) the deposition of organic-rich sediments (TOC &gt; 10%) coupled with sulphate-reduction processes in the deepest areas of the lake, (3) an important decrease in terrigenous supplies and (4) a long-term increase in δ18O of matrix-supported carbonates. This early Rupelian forced regression of the Vistrenque lacustrine system is interpreted to result from a regional decrease in precipitation in response to global cooling during the Eocene-Oligocene Transition (EOT). The final infill of the Vistrenque lake system (late Rupelian-early Chattian) and the onset of a floodplain occurred in more humid conditions during a stage of decreased activity of the Nîmes Fault, prior to or during an early stage of the Liguro-Provençal rifting.

Pedobiological properties of a lignite spoil heap in the Provence coal mine basin (south-east of France)

The aim of this study was to investigate the bio-physico-chemical properties of soils developed on dumps originating from lignite extraction and to decipher the respective roles of the geomorphology and the presence of lignite on the biogeochemical characteristics of these soils. Soils from the Armand spoil heap, located in Peypin (Bouches-du-Rhône, France), and natural neighboring Mediterranean soils without lignite were sampled and compared. Lignite presence was assessed by 13C CPMAS NMR spectroscopy allowing for the quantification of C pools such as aromatic C groups, which are characteristic signature of lignite. Physico-chemical (texture, pH, organic C, carbonate, total N, total S, CEC), mineralogical and biological (enzyme activities: β-glucosidase, arylsulfatase, acid phosphatase, arylamidase, lipase and fluorescein diacetate hydrolase; Oxitop basal respiration and Biolog® catabolic profile) parameters were analyzed in the two types of soil. Microbial activities were higher in the natural soils than in the spoil heap soils, while spoil heap samples exhibited enriched aromatic-C pools. Some variables exhibited a gradient along the slope: carbonate and sand contents were larger at the bottom of the heap while clay content, CEC, organic C and C/N ratio were larger at the top of the heap. On the contrary, microbiological activities did not follow any structured pattern according to the slope and appeared distributed as patches. Variance partitioning combined with multiple linear regressions demonstrated that the 13C NMR quality of soil organic matter was the main structuring factor of microbial properties, which were in most cases reduced by the presence of lignite.

Pinus halepensis and P. brutia provenances present similar resilience to drought despite contrasting survival, growth, cold tolerance and stem quality: Insights from a 45 year-old common garden experiment

To improve forest management strategies in the context of ongoing climate change, a better understanding of the inter- and intra-specific variability of tree performance is needed. Pinus halepensis and Pinus brutia, two major Mediterranean species providing crucial ecosystem services to human populations, have attracted increasing attention as potential candidates for assisted migration in the last decades for their growth performance and adaptation to drought. In this study, we compared 12 provenances of P. halepensis and 13 provenances of P. brutia originating from all around the Mediterranean basin in a common garden experiment established in 1976 in southeast France to identify the best species and provenances. Tree survival, circumference and height, as well as stem straightness and the presence of defects were measured and estimated based on forest inventories conducted in 1983, 1988, 1996 and 2021–22. In 2021, 427 trees were also cored and the resulting tree-ring width series were used to assess radial growth resistance, recovery and resilience to drought. Inter-individual variations in competition intensity were taken into account using a distance-dependent competition index, and did not show any significant relationship with tree resilience to drought, while it was negatively related with tree growth and positively with stem quality. We found only marginal differences among species and provenances in terms of growth response to drought. In contrast, there were strong inter- and intra-specific differences in terms of survival, cold tolerance, growth, and stem quality with P. brutia performing better than P. halepensis on average. Interestingly, provenances performances were not related to the climatic conditions at their origins suggesting that the observed inter- and intra-specific variability was not shaped by climatic gradients. This study is the first to compare P. halepensis and P. brutia resilience to drought and provides insights for the assisted migration of those species.

Overview of the Genetic Causes of Hereditary Breast and Ovarian Cancer Syndrome in a Large French Patient Cohort.

The use of multigene panel testing for patients with a predisposition to Hereditary Breast and Ovarian Cancer syndrome (HBOC) is increasing as the identification of mutations is useful for diagnosis and disease management. Here, we conducted a retrospective analysis of BRCA1/2 and non-BRCA gene sequencing in 4630 French HBOC suspected patients. Patients were investigated using a germline cancer panel including the 13 genes defined by The French Genetic and Cancer Group (GGC)-Unicancer. In the patients analyzed, 528 pathogenic and likely pathogenic variants (P/LP) were identified, including BRCA1 (n = 203, 38%), BRCA2 (n = 198, 37%), PALB2 (n = 46, 9%), RAD51C (n = 36, 7%), TP53 (n = 16, 3%), and RAD51D (n = 13, 2%). In addition, 35 novel (P/LP) variants, according to our knowledge, were identified, and double mutations in two distinct genes were found in five patients. Interestingly, retesting a subset of BRCA1/2-negative individuals with an expanded panel produced clinically relevant results in 5% of cases. Additionally, combining in silico (splicing impact prediction tools) and in vitro analyses (RT-PCR and Sanger sequencing) highlighted the deleterious impact of four candidate variants on splicing and translation. Our results present an overview of pathogenic variations of HBOC genes in the southeast of France, emphasizing the clinical relevance of cDNA analysis and the importance of retesting BRCA-negative individuals with an expanded panel.

First observations of Ruminapaivae Lowe, 1861 (Mollusca, Gastropoda) in the south-east of France, based on taxonomic clarifications.

Amongst the genus Rumina, R.paivae was decribed from North Africa for the first time by Lowe in 1861 on the basis of a limited number of samples. During the 19th and 20th centuries, it was described several times, under different names and different ranks leading to a taxonomic imbroglio before being forgotten. In 2002, Mienis rehabilitated R.paivae, but Prevot et al. (2013, 2014) considered it as a large phenotype of R.decollata Linnaeus (1758) on the basis of genetic and anatomical studies. In this study, we present morphological and anatomical comparisons and differences between two groups of shells collected in France and considered as R.decollata. Using seven morphological characters related to the size and one to the microscopic sculptures of the shell and two related to the eggs and the colours of the morphs, we attribute these two groups to two morphologically described species: R.paivae and R.decollata. We propose a way to easily distinguish them from each other. With regard to their distribution, morphology and genetics, we discuss their relative systematic position. Moreover, in this study, we report for the first time R.paivae, a given north African taxa, in the south-ast of France, in Marseille.