Biology subjects

Gavory, F.

Publications and source records attributed to Gavory, F..

5 recordsLinked to original sources

bioRxiv2026

Ocean-scale transcriptomic analysis of corallicolids (Apicomplexa) reveals their ubiquity and molecular interactions with Pocillopora corals.

Corals are complex holobionts, encompassing numerous prokaryotes, viruses, and protists. This associated microbial community strongly influences coral health and its resilience to global ocean warming. Corallicolid apicomplexans are widespread coral-infecting parasites, yet their impact on the coral host remains poorly understood. This knowledge gap largely stems from the low abundance of these parasites in coral tissues, which makes them difficult to isolate and access to their genetic material. Here we analyzed nearly 1,000 Pocillopora coral colonies collected from 32 islands during the Tara Pacific expedition to identify the drivers of corallicolid prevalence and abundance. Corallicolids were detected in almost all Pocillopora colonies with variable relative abundances between islands. The high abundance of specific corallicolid populations correlates with seawater temperature and levels of host protein carbonylation. We used a large collection of 297 metatranscriptomes to assemble a corallicolid transcriptome and we identified apicomplexan parasite signature genes, including the GRA9 and PV2 confirming the close phylogenetic relationship with the family of Eimeriidae. Gene expression patterns indicate that the high abundance of corallicolids correlates with a high transcription of genes encoding apical complex proteins and genes involved in the control of host immune defenses. Overall, this study provides new insights into corallicolid biology and its interaction with the coral host by combining a newly generated transcriptome with a large-scale sampling of Pocillopora corals across the Pacific Ocean.

genomics↗

bioRxiv2025

Scratching on French PDO cheese surfaces sheds light on an unexplored microbial genomic and metabolic diversity

Cheeses are fermented dairy products consumed worldwide. Their global diversity results from various local variables, including technological practices, as well as the metabolic activity of diverse microorganisms. In Europe, this typicity is exemplified by Protected Designation of Origin (PDO) cheeses, for which genetic diversity remains largely unexplored. Combining culturomics (n = 373 bacterial genomes) and metagenomic (n = 146 metagenomes), we performed a national-scale survey of the microbial diversity encompassing 44 French PDO cheeses. Taxonomic (bacteria, fungi and viruses) and functional profiling reveal a high diversity in the cheese rind, mainly driven by the cheese technology. We also reconstructed 1,119 bacterial metagenome-assembled genomes (MAGs) encompassing seven phyla, including Actinomycetota, Bacillota, Pseudomonadota and Bacteroidota. Using GTDB as a reference, we identified 221 MAGs encompassing 46 genera, as well as 44 bacterial isolate genomes encompassing eight genera, which represent potentially 81 new species (based on <95% ANI). These species were particularly numerous among the genera Halomonas, Psychrobacter and Brachybacterium. Similar results were observed when compared with the cFMD database. We combined our genomic and metagenomic datasets into a catalog of 26.2 million protein clusters, with 50% of these clusters remaining unassigned to a known function and taxonomy. We illustrated the potential of this resource by searching for methionine gamma-lyase (MGL), an enzyme playing a significant role in cheese flavor. This protein was predominantly found in Pseudoalteromonas, a potentially new MGL-producing genus, Serratia, Pseudomonas, Proteus and Hafnia, and its prevalence varied with cheese technology. Our study provides a substantial genomic resource for food microbiologists and cheesemakers to further explore the biotechnological potential of PDO cheese biodiversity.

microbiology↗

bioRxiv2025

Genomics-based quantitative biogeography of marine plankton

Marine plankton are key drivers of ocean productivity and global carbon cycling, yet their quantitative biogeography remains poorly characterized. Environmental genomic datasets are inherently compositional, restricting analyses to relative abundances and limiting their integration into ecological and biogeochemical models. Here we combine DNA mass measurements, filtered seawater volumes, and metagenomic relative abundances to generate absolute estimates of cell concentrations and carbon biomass of plankton across the global ocean. Leveraging thousands of samples, this approach provides quantitative estimates for hundreds of eukaryotic and thousands of prokaryotic environmental genomes, unveiling ecological associations not captured by compositional data. Using the psbO marker gene, we reconstruct quantitative biogeographies of photosynthetic lineages and, through global-scale modeling, project their distributions to generate quantitative maps of phytoplankton communities across the worlds ocean. By bridging genomic data with biogeochemical metrics, this study provides novel resources for integrating plankton at genomic resolution into next-generation biogeochemical models.

genomics↗

bioRxiv2024

An unexplored diversity for adaptation of germination to high temperatures in Brassica species

Elevated temperatures inhibit the germination of a concerning number of crop species. One strategy to mitigate the impact of warming temperatures is to identify and introgress adaptive genes into elite germplasm. Diversity must be sought in wild populations, coupled with an understanding of the complex pattern of adaptation across a broad range of landscapes. By investigating the landraces, wild, and feral populations of Algeria, Italy, France, Slovenia, Spain, and Tunisia, we assessed the response of germination to temperature increase in an unexplored diversity of 117 accessions of B. rapa and 66 of B. oleracea. Our results show that both species exhibit heat tolerance to the temperature range tested, especially B. rapa with an increase in speed and uniformity of germination time, as well as an increase in germination rate as temperature increased. As for B. oleracea accessions, the ability to germinate under heat conditions depended on the geographical origin; in particular, southern populations showed a higher germination rate than northern populations, possibly in relation to their warmer climates of origin. These findings highlight the complex interplay between domestication, feralization, and current agronomic practices in shaping germination characteristics in Brassica species.

evolutionary biology↗

bioRxiv2019

Genomic evidence for global ocean plankton biogeography shaped by large-scale current systems

Biogeographical studies have traditionally focused on readily visible organisms, but recent technological advances are enabling analyses of the large-scale distribution of microscopic organisms, whose biogeographical patterns have long been debated. Here we assessed the global structure of plankton geography and its relation to the biological, chemical and physical context of the ocean (the seascape) by analyzing metagenomes of plankton communities sampled across oceans during the Tara Oceans expedition, in light of environmental data and ocean current transport. Using a consistent approach across organismal sizes that provides unprecedented resolution to measure changes in genomic composition between communities, we report a pan-ocean, size-dependent plankton biogeography overlying regional heterogeneity. We found robust evidence for a basin-scale impact of transport by ocean currents on plankton biogeography, and on a characteristic timescale of community dynamics going beyond simple seasonality or life history transitions of plankton.

ecology↗