Overview
- University of St Andrews researchers report a marked rise in transcript isoforms per gene at the invertebrate-to-vertebrate transition, published in BMC Biology (2026).
- This increase is concentrated in transcription factor effectors at the ends of key intercellular signaling pathways that govern developmental decisions.
- New long-read datasets from a sea squirt (invertebrate), a lamprey (early vertebrate) and a frog resolved full-length transcripts to quantify isoform diversity with greater precision.
- The pattern suggests vertebrate complexity expanded by diversifying outputs of existing signaling genes rather than broadly adding new genes.
- Authors highlight the need for functional assays to test isoform roles and note potential implications for precision therapies targeting pathways often involved in disease.