London Calling 2023: Oxford Nanopore long-read RNA sequencing enables precise RNA isoform discovery and quantification in human brains

Nanopore long-read sequencing technologies can sequence entire RNA molecules in a single read, allowing researchers to accurately quantify expression for the complete set of RNA isoform species. This is a major improvement over past studies where, due to the limitations of short-read sequencing, researchers condensed all RNA isoforms into a single gene measurement. Here, we sequenced 12 aged human frontal cortex samples (six controls and six with Alzheimer’s disease) from post-mortem autopsy tissue. We discovered 245 new gene bodies and 428 new RNA isoforms in annotated gene bodies. Among these 428 new isoforms, 49 were from medically relevant genes, such as MAOB. Lastly, we identified 3,309 gene bodies expressing multiple RNA isoforms in a human frontal cortex, including genes implicated in Alzheimer’s disease, such as MAPT(4), CLU(4), APP(5), PSEN1(5), and BIN1(7). These results highlight the importance of accurately quantifying all RNA isoforms within a gene, as any of them could be differentially expressed in disease tissue.