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Biology subjects

Gairin, E.

Publications and source records attributed to Gairin, E..

6 recordsLinked to original sources

RadarOmics: Intuitive visualisation of multidimensional omics data in ecological, evolutionary, and developmental studies

Interpreting high-dimensional omics datasets requires visualisation tools that reveal coordinated responses across multiple biological processes. Existing approaches such as heatmaps or enrichment plots typically present processes independently and struggle to convey system-level patterns as experimental complexity increases. We developed RadarOmics, an R package that integrates multidimensional omics data using multi-axis radar visualisations. RadarOmics performs dimensional reduction (based on scaling, Principal Component Analyses, or Linear Discriminant Analyses) for predefined biological processes to extract a representative value for each sample and process of interest. These values are displayed in a circular radar layout, enabling rapid identification of global trends, outliers, and trade-offs among biological functions. Using transcriptomic datasets from anemonefish metamorphosis and zebrafish chemical exposure assays, we show that radar-based visualisations can reveal coordinated molecular responses that are less readily captured with traditional visualisation outputs. RadarOmics provides a flexible and intuitive framework for summarising and interpreting biological variation in ecological, evolutionary, and developmental omics studies, offering a compact system-level overview of molecular behaviour across complex experimental designs.

molecular biology↗

Cell-cell communication as underlying principle governing color pattern formation in fishes

The diverse pigmentation patterns of animals are crucial for predation avoidance and behavioral display, yet mechanisms underlying this diversity remain poorly understood. In zebrafish, Turing models have been proposed to explain stripe patterns, but it is unclear if they apply to other fishes. In anemonefish (Amphiprion ocellaris), we identified gja5b, a gene orthologous to zebrafish leopard and encoding a connexin involved in pigment cell communication, as responsible for the Snowflake phenotype. Using CRISPR/Cas9 and transgenesis, we recapitulate the Snowflake phenotype and show expression of gja5b in iridophores. A matching allele was recovered in zebrafish, revealing complementary requirements in both species. Our findings highlight conserved roles of gap junction mediated communication in pigment patterning across divergent teleosts.

developmental biology↗

Decoding the constraints acting on a coastal fish using landscape transcriptomics

Understanding how wild organisms respond to complex mixtures of environmental stressors remains a major challenge in ecology1,2. To move beyond laboratory-based studies of the effect of individual stressors on model species, landscape transcriptomics - the study of how genome-wide expression patterns reveal environmental conditions - has been suggested3. Here, we apply landscape transcriptomics to the damselfish Chrysiptera cyanea, a sentinel species from Okinawas coastal ecosystems, by sampling juveniles and adults across 18 sites from natural to urbanized habitats. We uncover a striking molecular signature of urbanization: fish from human-impacted sites exhibit elevated expression of genes involved in inflammation and immune responses. Remarkably, their transcriptomes resemble those of overfed individuals from laboratory feeding experiments - suggesting that urban reefs act as "fast food" environments, offering energy-rich diets while imposing chronic stress. This pattern is illustrated by the altered expression of key genes in metabolic and stress pathways (e.g., downregulation of ppargc1a and insrb, indicative of dietary intake surplus and insulin resistance; upregulation of interleukins, chemokines, toll-like receptors and caspase linked to the immune response and inflammation). Our results demonstrate that wild transcriptomes capture the invisible biological costs of environmental degradation, positioning fish as living biosensors for coastal ecosystem health.

bioinformatics↗

The genome of the sapphire damselfish Chrysiptera cyanea: a new resource to support further investigation of the evolution of Pomacentrids

The number of high-quality genomes is rapidly growing across taxa. However, it remains limited for coral reef fish of the Pomacentrid family, with most research focused on anemonefish. Here, we present the first assembly for a Pomacentrid of the genus Chrysiptera. Using PacBio long-read sequencing with a coverage of 94.5x, the genome of the Sapphire Devil, Chrysiptera cyanea was assembled and annotated. The final assembly consisted of 896 Mb pairs across 91 contigs, with a BUSCO completeness of 97.6%. 28,173 genes were identified. Comparative analyses with available chromosome-scale assemblies for related species identified contig-chromosome correspondences. This genome will be useful to use as a comparison to study the specific adaptations linked to symbiosis life of the closely related anemonefish. Furthermore, this species is present in most tropical coastal areas in the Indo-West Pacific and could become a model for environmental monitoring. This work will allow to expand coral reef research efforts and highlights the power of long-read assemblies to retrieve high quality genomes.

genomics↗

Validation of a novel fully immersive Virtual Reality setup with a behavioural study of freely-moving fish

Virtual Reality (VR) enables standardised stimuli to invoke behavioural responses in animals, however, in fish studies VR has been limited to either basic virtual stimulation projected below the bowl for freely-swimming individuals or a simple virtual arena rendered over a large field-of-view for head-restrained individuals. We developed a novel immersive VR setup with real-time rendering of animated 3D scenarios, validated in a proof of concept study on the behaviour of coral reef post-larval fish. Fish use a variety of cues to select a habitat during the recruitment stage, and to recognize conspecifics and predators, but which visual cues are used remains unknown. We measured behavioural responses of groups of five convict surgeonfish (Acanthurus triostegus) to simulations of habitats, static or moving shoals of conspecifics, predators, and non-aggressive heterospecifics. Post-larval fish were consistently attracted to virtual corals and conspecifics presented statically, but repulsed by their predators (bluefin jacks, Caranx melampygus). When simulated shoals passed nearby repeatedly, they were again attracted by conspecifics showing a tendency to follow the shoal, whereas they moved repeatedly to the back of the passing predator shoal. They also discriminated between species of similar sizes: they were attracted more to conspecifics than butterflyfish (Forcipiger longirostris), and repulsed more by predators than parrotfish (Scarus psittacus). The quality of visual simulations was high enough to identify between visual cues - size, body shape, colour pattern - used by post-larval fish in species recognition. Despite a tracking technology limited to fish 2D positions in the aquarium, preventing the real-time updating of the rendered viewpoint, we could show that VR and modern tracking technologies offer new possibilities to investigate fish behaviour through the quantitative analysis of their physical reactions to highly-controlled scenarios.

animal behavior and cognition↗

The chromosome-scale genome assembly of the yellowtail clownfish Amphiprion clarkii provides insights into melanic pigmentation of anemonefish

Anemonefish are an emerging group of model organisms for studying genetic, ecological, evolutionary, and developmental traits of coral reef fish. The yellowtail clownfish Amphiprion clarkii possesses species-specific characteristics such as inter-species co-habitation, high intra-species color variation, no anemone specificity, and a broad geographic distribution, that can increase our understanding of anemonefish evolutionary history, behavioral strategies, fish-anemone symbiosis, and color pattern evolution. Despite its position as an emerging model species, the genome of A. clarkii is yet to be published. Using PacBio long-read sequencing and Hi-C chromatin capture technology, we generated a high-quality chromosome-scale genome assembly initially comprised of 1,840 contigs with an N50 of 1,203,211 bp. These contigs were successfully anchored into 24 chromosomes of 843,582,782 bp and annotated with 25,050 protein-coding genes encompassing 97.0 % of conserved actinopterygian genes, making the quality and completeness of this genome the highest amongst all published anemonefish genomes to date. Transcriptomic analysis identified tissue-specific gene expression patterns, with the brain and optic lobe having the largest number of expressed genes. Further analyses revealed higher copy numbers of erbb3b (a gene involved in melanophore development) in A. clarkii compared to other anemonefish, thus suggesting a possible link between erbb3b and the natural melanism polymorphism observed in A. clarkii. The publication of this high-quality genome, along with A. clarkiis many unique traits, position this species as an ideal model organism for addressing scientific questions across a range of disciplines.

genomics↗