Genomic analysis reveals hidden population structure in commercially important flatfish species
A large-scale genomic study of common sole and European plaice in the Celtic Sea and western English Channel found that despite high connectivity, both species show signs of adaptive genetic differentiation. For sole, adaptive loci revealed two subpopulations separated near the western English Channel, while plaice showed three distinct populations across a broader European range. The findings have implications for fisheries management, suggesting that genetically distinct groups may require separate conservation strategies even when fish appear to mix freely.
Researchers used full-genome resequencing of 244 common sole and 189 European plaice to investigate population structure in the Celtic Sea and western English Channel, two of Europe's most commercially exploited flatfish species. For sole, neutral loci showed no evidence of reproductive isolation, but adaptive loci revealed two subpopulations divided near the western English Channel, consistent with earlier RAD-seq studies. Plaice showed no detectable structure within the Celtic Sea and western English Channel alone, but when broader European genomic datasets were incorporated, three clearly separated populations emerged: one in Iceland, one spanning the North Sea, Kattegat, and western Baltic, and one in the Celtic Sea and western English Channel. Three large chromosomal inversions were also identified in plaice, differing in frequency between regions and representing likely drivers of local adaptation. The study underscores the importance of distinguishing between neutral and adaptive genetic variation, as relying solely on neutral markers can obscure biologically meaningful population boundaries. These results suggest that current fisheries management units may not fully reflect the underlying genetic structure of these species, potentially affecting the sustainability of harvesting practices.
What's missing
The study does not address how the identified adaptive subpopulations or chromosomal inversions translate into specific phenotypic differences (e.g., growth rate, spawning timing, or habitat preference), which would be critical for translating genetic findings into concrete fisheries management recommendations. Additionally, the study is a preprint and has not yet undergone peer review, so findings should be treated as preliminary.
What different sources said
- bioRxivCenter
Genomics reveals population structure despite high connectivity of common sole, Solea solea, and European plaice, Pleuronectes platessa, in the Celtic Sea and western English Channel.
Related
Gut Bacteria Enzyme Found to Break Down Heat-Processed Food Compounds, Producing Novel Biogenic Amines
Researchers have discovered that an enzyme in common gut bacteria can degrade N-epsilon-carboxymethyllysine (CML), a compound formed during thermal food processing, producing previously unknown biogenic amines. The enzyme, ornithine decarboxylase SpeC from enterobacteria, acts on CML and related modified lysine derivatives through a low-level 'underground' catalytic activity. This finding suggests a previously unrecognized communication axis between thermally processed dietary compounds and gut microbial physiology, with potential implications for host health.
Full-Length Gene Sequencing Reveals Two Distinct Bacterial Communities in Black-Legged Ticks Expanding Into Canada
Researchers used Oxford Nanopore full-length 16S rRNA gene sequencing to characterize the microbiome of Ixodes scapularis black-legged ticks collected in Nova Scotia, Canada, distinguishing between tick-adapted bacteria and environmentally acquired bacteria. The study comes as I. scapularis — the primary vector of Lyme disease — is rapidly expanding northward into Canada due to climate change. The findings suggest that environmentally derived bacteria in tick microbiomes are not mere contamination, which has implications for how tick microbiome data is collected and interpreted across surveillance studies.
Study Identifies Metabolic Link Between Cell Envelope Stress and Biofilm Formation in Bacteria
Researchers have discovered that the metabolite acetyl-CoA directly inhibits enzymes that degrade the bacterial signaling molecule c-di-GMP, connecting cell envelope biosynthesis stress to biofilm formation in Pseudomonas aeruginosa. The study found that sub-inhibitory concentrations of antibiotics targeting early peptidoglycan biosynthesis — but not other antibiotic classes — elevate c-di-GMP levels by reducing phosphodiesterase activity, with acetyl-CoA competing for the enzyme active site. Because the relevant enzyme domain is broadly conserved across bacterial species, this checkpoint mechanism may be widespread and could have implications for understanding antibiotic-induced biofilm responses.