Biology subjects

Vidal-Dupiol, J.

Publications and source records attributed to Vidal-Dupiol, J..

At least 19 recordsLinked to original sources

bioRxiv2026

Decoupling epigenetic variation from genetic variation reveals complementary dimensions of coral eco-evolutionary dynamics

Understanding how intraspecific diversity is structured is essential for predicting the eco-evolutionary trajectories of populations, especially under rapid environmental change. While such diversity has been extensively studied from a genetic perspective, much less is known about the distribution and ecological relevance of epigenetic variation within natural populations. To address this question, we focused on two species of reef-building corals belonging to distinct functional groups, Pocillopora acuta and Acropora hyacinthus, sampled across the South Pacific (New Caledonia, Fiji, French Polynesia). Using genome-wide Enzyme-Methyl sequencing, we jointly analyzed genetic (SNPs) and DNA methylation (CpGs) variation, while explicitly disentangling genetically associated from genetically independent epigenetic variation. Genetic and epigenetic structure showed contrasting spatial patterns, reflecting distinct temporal and ecological components of population dynamics. Genetic structure was strongest between archipelagos and followed an isolation-by-distance pattern consistent with long-term evolutionary processes. In contrast, epigenetic variation converged between colonies from different archipelagos. At finer spatial scales within archipelago, genetically independent epigenetic variation exhibited stronger structure than both genetic and genetically associated epigenetic variation, likely reflecting local environmental conditions. Together, our results show that genetic and epigenetic variation provide complementary insights into the eco-evolutionary processes shaping intraspecific diversity.

evolutionary biology↗

bioRxiv2025

Multi-Omics Reprogramming Drives a Counterintuitive Reversal of Disease Susceptibility During Ageing

Ageing is a progressive and irreversible biological process characterized by the deterioration of physiological functions and increased vulnerability to mortality. Although extensively studied in vertebrates, ageing in long-lived invertebrates remains comparatively unexplored. While ageing typically leads to greater susceptibility to infectious diseases, a striking and unexpected reversal was identified in oysters: older oysters exhibit markedly increased tolerance to the Pacific Oyster Mortality Syndrome (POMS), a panzootic disease primarily driven by the OsHV-1 herpesvirus and responsible for severe losses in global aquaculture. To investigate this counterintuitive pattern, we challenged oysters aged 4, 16, and 28 months from four biparental families and conducted an integrative multi-omics analysis, including epigenomics, transcriptomics, and metabolomics on the two families showing the strongest age-related increase in survival. Our results reveal that ageing in Magallana gigas is characterized by coordinated epigenetic, transcriptional, and metabolic reprogramming that reduces host permissiveness to POMS. We show that the epigenetic remodeling of key immune regulators (e.g., Toll-like receptors, MyD88) aligns with transcriptional rewiring of NF-{kappa}B and ubiquitin pathways, producing a finely tuned innate immune state marked by enhanced antiviral activity but reduced antibacterial responsiveness. We also identify age-related repression of mTOR signaling, likely promoting autophagy and improving viral control. These regulatory changes are tightly linked to metabolic adjustments, including reduced TCA cycle flux, remodeled nitrogen metabolism, and altered glutathione dynamics, which collectively support a stress-tolerant, energy-conserving phenotype. Together, our findings reveal a fundamental evolutionary trade-off: juveniles prioritize growth at the cost of viral susceptibility, whereas adults invest in cellular maintenance and antiviral preparedness.

genomics↗

bioRxiv2025

Bacteria with antibacterial activities isolated from Magallana gigas microbiota as potential probiotics against Vibrio aestuarianus infections in oyster farming

IntroductionOyster farming is a significant industry worldwide, but it is threatened by various diseases such as Pacific Oyster Mortality Syndrome or vibriosis. V. aestuarianus is a major cause of mortality for market-size oysters, resulting in significant economic losses for oyster farmers. Among the various control methods developed, probiotics appear to be a promising approach. More specifically, the use of the antibacterial activity of bacteria from the natural microbiota of the oyster Magallana gigas appears to be a sustainable solution against V. aestuarianus infections. ResultsOur study investigated the probiotic potential of bacteria isolated from the microbiota of M. gigas oysters. We screened a collection of 334 bacteria against eight target pathogens, including V. aestuarianus, and identified 78 bacteria with antibacterial activity for which eight retained this activity in their culture supernatants. Five strains were selected for further testing and exposed to oysters prior to V. aestuarianus infection. Our results show that four strains significantly reduced oyster mortality, with a maximum reduction of 70%. In addition, changes in oyster microbiota composition were observed following exposure, but the administered bacteria were not detected in the microbiota. ConclusionOur findings demonstrate the potential of oyster microbiota-derived bacteria as probiotics for disease control in oyster farming. This approach could provide a sustainable and environmentally friendly solution for the oyster farming industry. Further research is needed to understand the underlying mechanisms and to develop effective probiotic-based strategies for preventing V. aestuarianus infection.

microbiology↗

bioRxiv2025

Experimentally mimicking 30 years of Magallana gigas infections with the OsHV-1 virus reveals evolution through positive selection

Ostreid herpesvirus 1 (OsHV-1) poses a significant threat to the global oyster farming industry, causing substantial economic losses due to mortality outbreaks. While OsHV-1 primarily affects the Pacific oyster Magallana gigas, it has also been associated with mortality events in various other host species. Despite progress in understanding OsHV-1 epidemiology, important knowledge gaps remain regarding its evolutionary mechanisms and adaptation to host genetic backgrounds. This study uses experimental evolution and extensive genomic analysis to investigate the dynamics of OsHV-1 evolution in response to oyster host genetic variation. Our results show that genetic mutations, particularly transitions and transversions, play a key role in shaping viral populations, contributing to a trend toward genetic homogenization. Notably, stronger positive selection signals were observed in viral genomes isolated from oyster populations with higher susceptibility, suggesting adaptation of viral genotypes to specific host genetic backgrounds. These findings shed light on the complex evolutionary dynamics of OsHV-1 and its interactions with oyster hosts. Understanding how this virus adapts to host genetic diversity is crucial for developing strategies to mitigate its impact on the oyster farming industry and provides valuable insights into the broader mechanisms of viral evolution in response to host variation.

evolutionary biology↗

bioRxiv2024

Benchmarking of Chromatin Immunoprecipitation (ChIP-Seq) methods in the Pacific oyster Magallana gigas

Chromatin Immunoprecipitation sequencing (ChIP-seq) is the method of choice to generate chromatin landscapes across genomes. The scarcity of literature on ChIPseq and absence of a canonical "gold standard" method in mollusks and especially the pacific oyster Magallana gigas, prompted us to compare four ChIP-seq methodologies (Native-ChIP, Crosslink-ChIP, ChIPmentation and Cut & Tag) to find the most suitable method for this species. Our results show that Cut & Tag performs best and ChIPmentation worst. We hypothesize that the reason for this lies in a particularly fragile chromatin structure around genes in the oyster.

molecular biology↗

bioRxiv2024

Microbial education plays a crucial role in harnessing the beneficial properties of microbiota for infectious disease protection in Crassostrea gigas

BackgroundRecently, the frequency and severity of marine diseases have increased in association with global changes, and molluscs of economic interest are particularly concerned. Among them, the Pacific oyster (Crassostrea gigas) production faces challenges from several diseases such as the Pacific Oyster Mortality Syndrome (POMS) or vibriosis. Various strategies such as genetic selection or immune priming have been developed to fight some of these infectious diseases. The microbial education, which consist of exposing the host immune system to beneficial microorganisms during early life stages is a promising approach against diseases. This study explores the concept of microbial education using controlled and pathogen-free bacterial communities and assesses its protective effects against POMS and Vibrio aestuarianus infections, highlighting potential applications in oyster production. ResultsWe demonstrate that it is possible to educate the oyster immune system by adding microorganisms during the larval stage. Adding culture based bacterial mixes to larvae protects only against the POMS disease while adding whole microbial communities from oyster donors protects against both POMS and vibriosis. The efficiency of the immune protection depends both on oyster origin and on the composition of the bacterial mixes used for exposure. No preferential protection was observed when the oysters were stimulated with their sympatric strains. We further show that the added bacteria were not maintained in the oyster microbiota after the exposure, but this bacterial addition induced long term changes in the microbiota composition and oyster immune gene expression. ConclusionOur study reveals successful immune system education of oysters by introducing beneficial micro-organisms during the larval stage. We improved the long-term resistance of oysters against critical diseases (POMS disease and Vibrio aestuarianus infections) highlighting the potential of microbial education in aquaculture.

microbiology↗

bioRxiv2024

Exploring thermal tolerance across time and space in a tropical bivalve, Pinctada margaritifera

Ectotherms vulnerability to climate change is predicted to increase with temperature variations. Still, translating laboratory observations of organisms heat stress responses to the natural fluctuating environment remains challenging. In this study, we used an integrative framework combining insights from the TDT curves and physiological reaction norms, to precisely capture Pinctada margaritifera stage -specific thermal tolerance. On a second hand, this study aimed to explore applicability of the model of accumulation of thermal injury, by making in situ predictions at three contrasting sites across French Polynesia. By working with two life stages (early planktonic vs. spat), our study revealed an ontogenetic shift in lethal (CTmax) and sub-lethal (Tc) thermal limits, with higher vulnerability for early larval stages. Cumulative injury calculations resulted in thermal failure (100% injury) for larvae within 12 and 22 h, at the most extreme site (Nuku Hiva; T{degrees}C > 38{degrees}C), and warm lagoon (Reao Atoll), respectively. While substantial damages accumulated in spats, when exposed to consecutive extreme tides (Nuku Hiva) for 8 days. Overall, our results revealed that P. margarifiera is living closer to their upper thermal limits than previously estimated, and inhabit environments where important reduction of settlement and heat stress are already occurring during warmest months.

physiology↗

bioRxiv2024

Reconstructing the dynamics of past coral endosymbiotic algae communities using coral ancient DNA (coraDNA)

Most scleractinian corals are drastically threatened due to global changes but some colonies are intriguingly resistant to heat stress. Coral thermal tolerance partly relies on genomic determinism among the cnidarian compartment but also on the physiology of their associated symbiotic algae (Symbiodiniaceae). In fact, some corals can shift and/or shuffle their associated Symbiodiniaceae communities to temporally cope with heat stress. So far coral adjustments of their endosymbiotic algae were mainly observed at short-term evolutionary time scales and we lack a general vision of coral holobiont evolution at broader timescales. We here combined the use of ancient DNA from a coral core and a metabarcoding approach, to retrace past Symbiodiniaceae communities associated with a living colony of Porites lobata from New Caledonia over the last century. We were able to extract ancient DNA along the coral core at 19 time points dating back to the 1870s. Overall, we detected 13 OTUs, nine of which were affiliated to the Symbiodiniaceae Cladocopium clade, one to Azadinium spinosum (Dinophycae); one to the host P. lobata, the two other OTUs remained unidentified. One OTU was largely predominant and was ubiquitous over all samples. The number of OTUs was marginally correlated to the total number of sequences per sample but not to the age of the coraDNA sample. We found a generally stable core microbiota associated with P. lobata, although drastic change in community composition was observed in coraDNA samples corresponding to an extreme hot winter temperature event. More generally, this study paves the way for further investigations on the evolutionary dynamics of coral holobionts at the colony level over large temporal scales.

evolutionary biology↗

bioRxiv2023

Epigenetic then genetic variations underpin rapid adaptation of oyster populations (Crassostrea gigas) to Pacific Oyster Mortality Syndrome (POMS)

Disease emergence is accelerating in response to human activity-induced global changes. Understanding the mechanisms by which host populations can rapidly adapt to this threat will be crucial for developing future management practices. Pacific Oyster Mortality Syndrome (POMS) imposes a substantial and recurrent selective pressure on oyster populations (Crassostrea gigas). Rapid adaptation to this disease may arise through both genetic and epigenetic mechanisms. In this study, we used a combination of whole exome capture of bisulfite-converted DNA, next-generation sequencing, and (epi)genome-wide association mapping, to show that natural oyster populations differentially exposed to POMS displayed signatures of selection both in their genome (single nucleotide polymorphisms) and epigenome (CG-context DNA methylation). Consistent with higher resistance to POMS, the genes targeted by genetic and epigenetic variations were mainly related to host immunity. By combining correlation analyses, DNA methylation quantitative trait loci, and variance partitioning, we revealed that a third of the observed phenotypic variation was explained by interactions between the genetic sequence and epigenetic information, [~]14% by the genetic sequence, and up to 25% by the epigenome alone. Thus, as well as genetic adaptation, epigenetic mechanisms governing immune responses contribute significantly to the rapid adaptation of hosts to emerging infectious diseases.

evolutionary biology↗

bioRxiv2023

Cooperation and cheating orchestrate Vibrio assemblages and polymicrobial synergy in oysters infected with OsHV-1 virus

Polymicrobial diseases significantly impact the health of humans and animals but remain understudied in natural systems. We recently described the Pacific Oyster Mortality Syndrome (POMS), a polymicrobial disease that impacts oyster production and is prevalent worldwide. Analysis of POMS-infected oysters on the French North Atlantic coast revealed that the disease involves co-infection with the endemic ostreid herpesvirus 1 (OsHV-1) and virulent bacterial species such as Vibrio crassostreae. However, it is unknown whether consistent Vibrio populations are associated with POMS in different regions, how Vibrio contribute to POMS, and how they interact with the OsHV-1 virus during pathogenesis. We resolved the Vibrio population structure in oysters from a Mediterranean ecosystem and investigated their functions in POMS development. We find that Vibrio harveyi and Vibrio rotiferianus are the predominant species found in OsHV-1-diseased oysters and show that OsHV-1 is necessary to reproduce the partition of the Vibrio community observed in the field. By characterizing the interspecific interactions between OsHV-1, V. harveyi and V. rotiferianus, we find that only V. harveyi synergizes with OsHV-1. When co-infected, OsHV-1 and V. harveyi behave cooperatively by promoting mutual growth and accelerating oyster death. V. harveyi showed high virulence potential in oysters and dampened host cellular defenses, making oysters a more favorable niche for microbe colonization. We next investigated the interactions underlying the co-occurrence of diverse Vibrio species in diseased oysters. We found that V. harveyi harbors genes responsible for the biosynthesis and uptake of a key siderophore called vibrioferrin. This important resource promotes the growth of V. rotiferianus, a cheater that efficiently colonizes oysters during POMS without costly investment in host manipulation nor metabolite sharing. By connecting field-based approaches, laboratory infection assays and functional genomics, we have uncovered a web of interdependencies that shape the structure and function of the POMS pathobiota. We showed that cooperative behaviors contribute to synergy between bacterial and viral co-infecting partners. Additional cheating behaviors further shape the polymicrobial consortium. Controlling such behaviors or countering their effects opens new avenues for mitigating polymicrobial diseases.

microbiology↗

bioRxiv2023

Transcriptomics of mussel transmissible cancer MtrBTN2 reveals accumulation of multiple cancerous traits and oncogenic pathways shared among bilaterians

Transmissible cancer cell lines are rare biological entities giving rise to diseases at the crossroads of cancer and parasitic diseases. These malignant cells have acquired the amazing capacity to spread from host to host. They have been described only in dogs, Tasmanian devils and marine bivalves. The Mytilus trossulus Bivalve Transmissible Neoplasia 2 (MtrBTN2) lineage has even acquired the capacity to spread inter-specifically between marine mussels of the Mytilus edulis complex worldwide. To identify the oncogenic processes underpinning the biology of these atypical cancers we performed transcriptomics of MtrBTN2 cells. Differential expression, enrichment, protein-protein interaction network, and targeted analyses were used. Overall, our results suggest the accumulation of multiple cancerous traits that way be linked to the long-term evolution of MtrBTN2. We also highlight that vertebrate and lophotrochozoan cancers could share a large panel of common drivers, which supports the hypothesis of an ancient origin of oncogenic processes in bilaterians.

cancer biology↗

bioRxiv2021

Population genomics of Pocillopora corals: insights from RAD-sequencing

Scleractinian corals are of great ecological interest as ecosystem engineer species. Accordingly, there is a wealth of studies on their adaptive abilities facing climate change. Such studies should rely on precise species and population delimitation. Nevertheless species delimitation in corals can be hindered by the lack of adequate genetic markers, by hybridization, and by morphological plasticity. Here we applied RAD sequencing to the study of species delimitation and genetic structure in populations of Pocillopora spp. from Oman and French Polynesia with the objectives to test primary species hypotheses based on mitochondrial DNA sequencing, and to study the genetic structure among sampling sites inside species. Regarding the varying levels of missing data observed among samples we tested different filtering strategy. The main genetic differentiation was observed between samples from Oman and French Polynesia, which also corresponded to different mitochondrial lineages and species hypotheses. In Oman, we did not observe any clear differentiation according to the main mitochondrial lineages considered here, nor between sampling sites. In French Polynesia where a single mitochondrial lineage was studied, we did not evidence any differentiation according to sampling sites. These results provide an additional example of the importance of using independent nuclear markers for the study of species delimitation. Our analyses also allowed the identification of clonal lineages in our samples, and to take them into account in our interpretations. We used simulations to study the impact of clonal reproduction on the distribution of statistics of genetic diversity and genetic structure among loci.

evolutionary biology↗

bioRxiv2019

Chromatin structure changes in Daphnia populations upon exposure to environmental cues - or - The discovery of Wolterecks \"Matrix\"

Phenotypic plasticity is an important feature of biological systems that is likely to play a major role in the future adaptation of organisms to the ongoing global changes. It may allow an organism to produce alternative phenotypes in responses to environmental cues. Modifications in the phenotype can be reversible but are sometimes enduring and can even span over generations. The notion of phenotypic plasticity was conceptualized in the early 20th century by Richard Woltereck. He introduced the idea that the combined relations of a phenotypic character and all environmental gradients that influence on it can be defined as \"norm of reaction\". Norms of reaction are specific to species and to lineages within species, and they are heritable. He postulated that reaction norms can progressively be shifted over generations depending on the environmental conditions. One of his biological models was the water-flee daphnia. Woltereck proposed that enduring phenotypic modifications and gene mutations could have similar adaptive effects, and he postulated that their molecular bases would be different. Mutations occurred in genes, while enduring modifications were based on something he called the Matrix. He suggested that this matrix (i) was associated with the chromosomes, (ii) that it was heritable, (iii) it changed during development of the organisms, and (iv) that changes of the matrix could be simple chemical substitutions of an unknown, but probably polymeric molecule. We reasoned that the chromatin has all postulated features of this matrix and revisited Wolterecks classical experiments with daphnia. We developed a robust and rapid ATAC-seq technique that allows for analyzing chromatin of individual daphnia and show here (i) that this technique can be used with minimal expertise in molecular biology, and (ii) we used it to identify open chromatin structure in daphnia exposed to different environmental cues. Our result indicates that chromatin structure changes consistently in daphnia upon this exposure confirming Wolterecks classical postulate.

evolutionary biology↗

bioRxiv2019

The tropical coral Pocillopora acuta has a mosaic DNA methylome, an unusual chromatin structure and shows histone H3 clipping

Pocillopora acuta is a hermatypic coral with a worldwide distribution and a strong ecological importance. Anthropogenic disturbances and global warming threaten it. Thermal stress can induce coral bleaching, a phenomenon in which the mutualistic symbiosis between the coral polyps host and its endosymbiotic unicellular algae is disrupted, and can lead to the death of entire colonies. Previous works have shown that soma clonal colonies display different levels of survival depending on the environmental conditions they previously faced. Epigenetic mechanisms are good candidates to explain this phenomenon. The clonal nature of a colony and the possibility of generating genetically identical colonies through propagation make corals an attractive model to study the impact of the environment on the epigenome. However, until now, no work had been published on the P. acuta epigenome. One of the main problems is caused by the intracellular location of Symbiodinium, which makes it complicated to isolate coral chromatin free of contamination by endiosymbiotic biological material. Here, (i) we describe a simple method to purify P. acuta chromatin, (ii) we provide the first description of a coral methylome, with a mosaic pattern of cytosine methylation principally in a CpG context (4% of all CpG), and (iii) we show that P. acuta, but not all corals, has an unusual chromatin structure, and displays histone H3 clipping.

molecular biology↗

bioRxiv2019

Sequencing, de novo assembly and annotation of the genome of the scleractinian coral, Pocillopora acuta

Coral reefs are the most divers marine ecosystem. However, under the pressure of global changes and anthropogenic disturbances corals and coral reefs are declining worldwide. In order to better predict and understand the future of these organisms all the tools of modern biology are needed today. However, many NGS based approaches are not feasible in corals because of the lack of reference genomes. Therefore we have sequenced, de novo assembled, and annotated, the draft genome of one of the most studied coral species, Pocillopora acuta (ex damicornis). The sequencing strategy was based on four libraries with complementary insert size and sequencing depth (180pb, 100x; 3Kb, 25x; 8kb, 12x and 20 kb, 12x). The de novo assembly was performed with Platanus (352 Mb; 25,553 scaffolds; N50 171,375 bp). 36,140 genes were annotated by RNA-seq data and 64,558 by AUGUSTUS (Hidden-Markov model). Gene functions were predicted through Blast and orthology based approaches. This new genomic resource will enable the development of a large array of genome wide studies but also shows that the de novo assembly of a coral genome is now technically feasible and economically realistic.

genomics↗

bioRxiv2019

Effects of temperature and pCO2 on the respiration, biomineralization and photophysiology of the giant clam Tridacna maxima

Such as many other reef organisms, giant clams are today confronted to global change effects and can suffer mass bleaching or mortality events mainly related to abnormally high seawater temperatures. Despite its strong ecological and socio-economical importance, its responses to the two most alarming threats linked to global change (i.e., ocean warming and acidification) still need to be explored. We investigated physiological responses of 4-years-old Tridacna maxima specimens to realistic levels of temperature and partial pressure of carbon dioxide (pCO2) (+1.5{degrees}C and +800 atm of CO2) predicted for 2100 in French Polynesian lagoons during the warmer season. During a 65-days crossed-factor experiment, individuals were exposed to two temperatures (29.2{degrees}C; 30.7{degrees}C) and two pCO2 (430 {micro}atm; 1212 {micro}atm) conditions. Impact of each parameter and their potential synergetic effect were evaluated on respiration, biomineralization and photophysiology. Kinetics of thermal and acidification stress were evaluated by performing measurements at different times of exposure (29, 41, 53, 65 days). At 30.7{degrees}C, the holobiont O2 production, symbiont photosynthetic yield, and density were negatively impacted. High pCO2 had a significant negative effect on shell growth rate, symbiont photosynthetic yield and density. Shell microstructural modifications were observed from 41 days in all temperature and pCO2 conditions. No significant synergetic effect was found. Today thermal conditions (29.2{degrees}C) appeared to be sufficiently stressful to induce a host acclimatization process. All these observations indicate that temperature and pCO2 are both forcing variables affecting T. maxima physiology and jeopardize its survival under environmental conditions predicted for the end of this century.

ecology↗

bioRxiv2018

Identifying conserved molecular mechanisms of thermo-acclimation in symbiotic organisms

Seawater temperature rise in French Polynesia has repeatedly resulted in symbiosis breakdown between giant clam (Tridacna maxima) and dinoflagellates (Symbiodinium spp.), particularly in small individuals. Herein, we explored the physiological and gene expression responses of the clam hosts and their photosynthetically active symbionts over a 65-day experiment in which clams were exposed to either normal or environmentally relevant elevated seawater temperatures. These data were combined with publicly available data for both free-living Symbiodinium (clades C1 and F) and Symbiodinium spp. in hospite with the coral Pocillopora damicornis. Gene module preservation analysis revealed that the function of the symbionts photosystem II was impaired at high temperatures, and this response was conserved across all holobionts and Symbiodinium clades examined. Similarly, activation of the phytohormone abscisic acid signaling and epigenetics modulation appeared to be a key response mechanisms for symbionts in hospite with giant clams exposed to high temperatures and also distinguish thermo-tolerant from thermo-sensitive Symbiodinium C1 phenotypes.

genomics↗

bioRxiv2018

Whole transcriptome sequencing and biomineralization gene architecture associated with cultured pearl quality traits in the pearl oyster, Pinctada margaritifera

BackgroundCultured pearls are unique gems produced by living organisms, mainly molluscs of the Pinctada genus, through the biomineralization properties of pearl sac tissue. Improvement of P. margaritifera pearl quality is one of the biggest challenges that Polynesian research has faced to date. To achieve this goal, a better understanding of the complex mechanisms related to nacre and pearl formation is essential and can now be approached through the use of massive parallel sequencing technologies. The aim of this study was to use RNA-seq to compare whole transcriptome expression of pearl sacs that had producing pearls with high and low quality. For this purpose, a comprehensive reference transcriptome of P. margaritifera was built based on multi-tissue sampling (mantle, gonad, whole animal), including different living stages (juvenile, adults) and phenotypes (colour morphotypes, sex).\n\nResultsStrikingly, few genes were found to be up-regulated for high quality pearls (n = 16) compared to the up-regulated genes in low quality pearls (n = 246). Biomineralization genes up-regulated in low quality pearls were specific to prismatic and prism-nacre layers. Alternative splicing was further identified in several key biomineralization genes based on a recent P. margaritifera draft genome.\n\nConclusionThis study lifts the veil on the multi-level regulation of biomineralization genes associated with pearl quality determination.

molecular biology↗