RT Journal Article SR Electronic T1 Widespread polycistronic transcripts in mushroom-forming fungi revealed by single-molecule long-read mRNA sequencing JF bioRxiv FD Cold Spring Harbor Laboratory SP 012542 DO 10.1101/012542 A1 Gordon, Sean P. A1 Tseng, Elizabeth A1 Salamov, Asaf A1 Zhang, Jiwei A1 Meng, Xiandong A1 Zhao, Zhiying A1 Kang, Dongwan A1 Underwood, Jason A1 Grigoriev, Igor V. A1 Figueroa, Melania A1 Schilling, Jonathan S. A1 Chen, Feng A1 Wang, Zhong YR 2014 UL http://biorxiv.org/content/early/2014/12/11/012542.abstract AB Genes in prokaryotic genomes are often arranged into clusters and co-transcribed into polycistronic RNAs. Isolated examples of polycistronic RNAs were also reported in some eukaryotes but their presence was generally considered rare. Here we developed a long-read sequencing strategy to identify polycistronic transcripts in several mushroom forming fungal species including Plicaturopsis crispa, Phanerochaete chrysosporium, Trametes versicolor and Gloeophyllum trabeum1. We found genome-wide prevalence of polycistronic transcription in these Agaricomycetes, and it involves up to 8% of the transcribed genes. Unlike polycistronic mRNAs in prokaryotes, these co-transcribed genes are also independently transcribed, and upstream transcription may interfere downstream transcription. Further comparative genomic analysis indicates that polycistronic transcription is likely a feature unique to these fungi. In addition, we also systematically demonstrated that short-read assembly is insufficient for mRNA isoform discovery, especially for isoform-rich loci. In summary, our study revealed, for the first time, the genome prevalence of polycistronic transcription in a subset of fungi. Futhermore, our long-read sequencing approach combined with bioinformatics pipeline is a generic powerful tool for precise characterization of complex transcriptomes.