Inter-individual gene expression variability implies stable regulation of brain-biased genes across organs in three ray-finned fishes.

Inter-individual gene expression variability in three ray-finned fishes is low for brain- and gonad-biased genes, indicating conserved regulation across organs.

• Why it matters: Understanding how gene expression variability relates to gene function and regulation in multicellular organisms remains limited, especially across different tissues sharing the same genetic background.
• What they did: Using multiplexed 3'-end bulk RNA sequencing, the study profiled transcriptomes from at least nine organs in zebrafish, Northern pike, and spotted gar, quantifying gene expression variability independently of mean expression.
• The result: Findings show that genes with broad expression are highly expressed and lowly variable, while organ-biased genes are highly variable, with brain- and gonad-biased genes exhibiting low variability across organs, implying organ-specific regulatory evolution.