Phenotypic variation among individuals provides the raw material for evolution, and gene expression is a key mediator between genetic and phenotypic variation. As for phenotypes, the range of gene expression is limited and biased by evolutionary and developmental constraints. Observed expression variability due to biomolecular stochasticity and cell-to-cell heterogeneity has been well-studied in isogenic populations of unicellular organisms. However, for multicellular organisms with a diversity of cells and tissues sharing the same genetic background, the interplay between expression variability, gene and organ function, and gene regulation remains an open question. Here, we use highly multiplexed 3'-end bulk RNA sequencing to generate transcriptome profiles spanning at least nine organs in outbred individuals of three ray-finned fish species: zebrafish, Northern pike, and spotted gar. Per organ, we quantify individual-to-individual gene expression variability independent of mean expression level. Lowly variable genes are enriched in cellular housekeeping functions whereas highly variable genes are enriched in stimulus-response functions. Furthermore, highly variable genes evolve under weaker purifying selection at the protein-coding sequence, indicating that intra-species expression variability predicts inter-species protein sequence divergence. Genes that are broadly expressed across organs are both highly expressed and lowly variable, whereas organ-biased genes are typically highly variable within their top organ. Among organ-biased genes, patterns of expression variance are dependent on the top organ. Specifically, brain- and gonads-biased genes have lowly variable expression across different organs, suggesting stabilizing selection. These patterns suggest that gene regulatory mechanisms evolve under organ-specific selective pressures.

En 2025, quatre scientifiques se sont vu·es recompensé·es par une bourse Ambizione du Fonds national suisse, leur permettant de rejoindre la communauté scientifique de la Faculté de biologie et de médecine (FBM) de l’Unil. Les subsides ont été attribués à Lily Fogg, Thomas Hitchcock, Alice Horisberger et Elisa Rioja Blanco.

Recommended dose of hepatitis B vaccine will be withheld from thousands of newborns by Danish researchers

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GHT-SELEX—high-throughput SELEX with fragmented genomic DNA—shows that transcription factors can be rather particular about which genomic loci they bind, and that C2H2 zinc finger proteins often engage different fingers at different sites.

The universal cell embedding foundation model learns to capture the organization and variation of cells by training on 36 million cells from hundreds of experiments, dozens of tissues and eight species.

The biological significance of non-coding RNAs has been increasingly appreciated as their roles in various cellular processes are uncovered. However, single-cell transcriptomic profiling of human samples has focused primarily on protein-coding genes ...

At its meeting on 20 and 21 May 2026 and upon application of Joël Mesot, President of ETH Zurich, the ETH Board appointed Stephen Quake, currently Professor at Stanford University, USA, as Full Professor of Biophysics and Biomedical Engineering at the D-BSSE and faculty member of the Basel Research Center for Child Health (BRCCH). A warm welcome, Stephen!

The spinal cord contains evolutionarily conserved cell types critical for motor function, sensory processing, and autonomic regulation, many of which are implicated in diverse neurological diseases and injuries. Yet the field lacks a comprehensive ...