Biology subjects

Calboli, F. C. F.

Publications and source records attributed to Calboli, F. C. F..

3 recordsLinked to original sources

bioRxiv2025

Fish Show Genetic Evolutionary Responses to River Regulation

Eco-hydraulics traditionally aims at managing riverine systems in a semi-natural state while meeting human demands, assuming aquatic species are static. However, evidence of rapid evolution suggests that ignoring evolutionary dynamics of fish species might limit long-term effectiveness of eco-hydraulics frameworks. It remains unclear how freshwater fish adapt to human perturbation. Why are some fish populations more resilient to human perturbation than others? What are the genetic mechanisms behind it? To answer these questions, we genotyped eleven populations of three-spined stickleback in a regulated river system and collected data on river morphology, connectivity, flow regimes, physico-chemistry and parasite abundance through a combination of field surveys and modelling. Gene-environment association analysis detected strong signals of genetic divergence associated with hydraulic features. Gene ontology analysis revealed evolutionary responses that primarily involve functions in the nervous and sensory systems. These findings demonstrate that fish can evolve in response to river regulation, highlighting the need to transition from eco-hydraulics toward eco-evo-hydraulics.

evolutionary biology↗

bioRxiv2024

Spleen gene expression is associated with mercury content in three-spined stickleback populations

Mercury can be very toxic at low environmental concentrations by impairing immunological, neurological, and other vital pathways in humans and animals. Aquatic ecosystems are heavily impacted by mercury pollution, with evidence of biomagnification through the food web. We examined the effect of mercury toxicity on the spleen, one of the primary immune organs in fish, in natural populations of the three-spined stickleback (Gasterosteus aculeatus Linnaeus, 1758). Our aim was to better understand adaptation to high mercury environments by investigating transcriptomic changes in the spleen. Three stickleback populations with mean Hg muscle concentrations above and three populations with mean Hg muscle concentrations below the European Biota Quality Standard of 20 ng/g wet weight were selected from the Scheldt and Meuse basin in Belgium. We then conducted RNA sequencing of the spleen tissue of 22 females from these populations. We identified 136 differentially expressed genes between individuals from populations with high and low mean mercury content. The 129 genes that were upregulated were related to the neurological system, immunological activity, hormonal regulation, and inorganic cation transporter activity. Seven genes were downregulated and were all involved in pre-mRNA splicing. The results are indicative of our ability to detect molecular alterations in natural populations that exceed an important environmental quality standard. This allows us to assess the biological relevance of such standards, offering an opportunity to better describe and manage mercury-associated environmental health risks in aquatic populations.

ecology↗

bioRxiv2019

Genome sequencing of the nine-spined stickleback (Pungitius pungitius) provides insights into chromosome evolution.

The Gasterostidae fish family hosts several species that are important models for eco-evolutionary, genetic and genomic research. In particular, a wealth of genetic and genomic data have been generated for the three-spined stickleback (Gasterosteus aculeatus), the ecologys supermodel, while the genomic resources for the nine-spined stickleback (Pungitius pungitius) have remained relatively scarce. Here, we report a high-quality chromosome-level genome assembly of P. pungitius consisting of 5,303 contigs (N50 = 1.2 Mbp) with a total size of 521 Mbp. These contigs were mapped to 21 linkage groups using a high-density linkage map, yielding a final assembly with 98.5% BUSCO completeness. A total of 25,062 protein-coding genes were annotated, and ca. 23% of the assembly was found to consist of repetitive elements. A comprehensive analysis of repetitive elements uncovered centromeric-specific tandem repeats and provided insights into the evolution of retrotransposons. A multigene phylogenetic analysis inferred a divergence time of about 26 million years (MYA) between nine- and three-spined sticklebacks, which is far older than the commonly assumed estimate of 13 MYA. Compared to the three-spined stickleback, we identified an additional duplication of several genes in the hemoglobin cluster. Sequencing data from populations adapted to different environments indicated potential copy number variations in hemoglobin genes. Furthermore, genome-wide synteny comparisons between three- and nine-spined sticklebacks identified chromosomal rearrangements underlying the karyotypic differences between the two species. The high-quality chromosome-scale assembly of the nine-spined stickleback genome obtained with long-read sequencing technology provides a crucial resource for comparative and population genomic investigations of stickleback fishes and teleosts.

genomics↗