London Calling 2023: Investigating RNA isoform expression using the IsoMix toolkit

Accurate quantification of genes and their mRNA products is essential to understanding health and disease. In humans, processes such as alternative splicing cause almost all genes to express multiple mRNA products (isoforms), which can have different functions. Long-read RNA sequencing can cover an entire mRNA sequence in a single read and so identify and quantify the isoforms present. Therefore, we have developed the IsoMix toolkit to enable the discovery, quantification, and characterization of RNA isoforms in both bulk and single-cell samples. With these tools we have discovered hundreds of novel isoforms of disease-risk genes and their likely proteomic consequences; tracked cell-type specific expression of isoforms during neuronal development; and quantified differential expression of isoforms between regions of the human brain. The characterisation of RNA isoforms with the IsoMix toolkit will enable a vastly improved understanding of gene isoforms and their biological and pathophysiological functions.