Biology subjects

Carpentier, C.

Publications and source records attributed to Carpentier, C..

5 recordsLinked to original sources

bioRxiv2026

A cryptic local genetic cluster in Northern France amid the European mosaic of flat oyster lineages revealed by integrating SNP array and whole-genome sequencing

The European flat oyster (Ostrea edulis), like numerous other oyster species, has been exploited for millennia and cultivated and translocated for centuries. Following a severe population decline, and in the context of ongoing conservation and restoration programs, genetic considerations must now be addressed to avoid mistakes. The objective of our study was to complement population genetic studies conducted at various scales along European coasts. Our sampling primarily targeted the French Atlantic, English Channel, and Mediterranean coasts, aiming to provide a fine-scale genetic characterization of populations in these regions. By integrating SNP array and low-coverage sequencing datasets, we obtained a comprehensive overview of the population genetic structure of Ostrea edulis across western Europe. Most previously identified clusters in Western Europe were confirmed. In France, populations assigned to these clusters exhibited notable within-patch homogeneity. However, two key findings emerged: (1) an extensive overlap zone between the Atlantic and western Mediterranean clusters, spanning at least from southern Portugal to southern France, and (2) the detection of a novel, clearly distinct cryptic cluster east of the English Channel, whose geographic range remains to be better delineated. These insights are critical for informing management decisions, particularly as restoration and conservation plans are currently being implemented across the species range.

genetics↗

bioRxiv2025

Network theory predicts ecosystem robustness across environmental conditions

Theory posits that a networks link-species relationship predicts how changes in species richness S lead to changes in the number of links L between species. This relationship quantifies resistance to secondary extinctions and therefore gives pivotal information on ecosystem robustness. However, changes in S often coincide with environmental shifts, which can lead to unexpected impacts on L. In this paper, we constructed link-species relationships from 18 ecosystems using 1081 observations collected across different environmental conditions. We found that environmental noise (unspecified spatio-temporal variation) and environmental gradients (directional change) profoundly affected ecological network size (S and L), community composition, and induced network rewiring, with a Novotnys rewiring index up to 0.47. Yet, we found the log(L) [~] log(S) relationship to be remarkably constant across environmental conditions. Only in two of the 18 ecosystems did we find changes in environmental conditions to shift the log(L) [~] log(S) relationship down, implying an overall drop in L but not in how species loss affects L. Our results show that network theory predicts ecosystem robustness across environmental gradients, which is encouraging for conservation.

ecology↗

bioRxiv2022

Cellular senescence in malignant cells promotes tumor progression in mouse and patient Glioblastoma

Glioblastoma (GBM) is the most common primary malignant brain tumor in adults, yet it remains refractory to systemic therapy. Elimination of senescent cells has emerged as a promising new treatment approach against cancer. Here, we investigated the contribution of senescent cells to GBM progression. Senescent cells were identified in patient and mouse GBMs. Partial removal of p16Ink4a-expressing malignant senescent cells, which make up less than 7 % of the tumor, modified the tumor ecosystem and improved the survival of GBM-bearing mice. By combining single cell and bulk RNA sequencing, immunohistochemistry and genetic knockdowns, we identified the NRF2 transcription factor as a determinant of the senescent phenotype. Remarkably, our mouse senescent transcriptional signature and underlying mechanisms of senescence are conserved in patient GBMs, in whom higher senescence scores correlate with shorter survival times. These findings suggest that senolytic drug therapy may be a beneficial adjuvant therapy for patients with GBM.

cancer biology↗

bioRxiv2019

Long term development of a realistic and integrated socio-ecological system

We developed a discrete and qualitative model of integrated socio-ecosystems, with the help of formal Petri nets. We illustrated such Petri nets in the case study of temporary marshes in the Mediterranean part of France, the Camargue delta, by integrating biotic, abiotic and human-related components along with their processes into the same interaction network. The model demonstrated that when marshes are exposed to extensive grazing the presence of marsh heritage species is facilitated by opening up the vegetation through various trajectories. This supports the commonly used management practice of extensive grazing to conserve certain protected habitats. With this Possibilistic approach, we identified all potential ecosystem trajectories and provided their differential (non-systematic) impacts on heritage species richness (number). Hence, we rigorously demonstrate with this new type of model that grazing benefits marsh species which are faced with competition from common grassland species. The detailed analysis of the explicit state space and trajectories allows exploring simultaneously the identification of a range of recommendations for management strategies.

ecology↗

bioRxiv2019

Fitness differences, not niche differences, limit species richness

A key question in ecology is what limits species richness. Modern coexistence theory presents the persistence of species as a balance between niche differences and fitness differences that favor and hamper coexistence, respectively. With most applications focusing on species pairs, however, we know little about if and how this balance changes with species richness. Here, we present the first mathematical proof that the average fitness difference among species increases with richness, while the average niche difference stays constant. Extensive simulations with more complex models and analyses of empirical data confirmed these mathematical results. Taken together, our work suggests that, as species accumulate in ecosystems, ever-increasing fitness differences will at some point exceed constant niche differences, limiting species richness. Our results contribute to the expansion of modern coexistence theory towards multi-species communities.

ecology↗