The Scent of Success: Decoding the Senegalese Sole's Love Life

For European fish farmers, the Senegalese sole presents a peculiar frustration: while wild-caught specimens breed freely, their captive-born sons (the F1 generation) seem entirely clueless when it comes to courtship. The leading theory is not a lack of desire, but a failure of communication—specifically, the chemical signalling processed by the olfactory system. To tackle this reproductive impasse, researchers have generated the first full-length hybrid transcriptome of the sole’s olfactory rosette.

By combining the precision of Illumina short-read sequencing with the depth of Oxford Nanopore long-reads, the team analysed the genetic output of fish across all ages and origins. The result is a comprehensive map comprising 20,670 active transcripts, including nearly 6,000 novel variations of known genes and 971 entirely new genetic discoveries. This data creates a high-resolution snapshot of how these demersal flatfish perceive their watery world.

The study paid particular attention to specific gene families responsible for detecting scents—OlfC, OR, ORA, and TAAR. These receptors are the molecular gatekeepers of social and environmental interaction. With this genomic blueprint in hand, aquaculture specialists can now investigate exactly which chemical keys are missing in the captive environment. Unlocking the genetic basis of olfaction could finally teach these shy farm-raised males how to interpret the scent of a mate, securing the future of the industry.