A comprehensive full-length transcriptome atlas across multiple organs of an Indian yak breed-Arunachali

Yak (Bos grunniens) is a high-altitude adapted bovine species native to the Himalayan and Tibetan plateau, thriving at elevations above 3000 m from msl under hypobaric hypoxia. Despite its remarkable physiological adaptations, a complete transcriptomic understanding across multiple organs remains limited. In this study, full-length transcriptome sequencing of 22 tissues was performed using PacBio Iso-Seq, generating over 200,000 high-quality non-redundant RNA transcripts. This dataset significantly improves yak genome annotation and reveals widespread isoform diversity, including thousands of novel transcripts and 4,319 high-confidence lncRNAs. Enrichment of key hypoxia-related pathways such as HIF-1, PI3K-Akt, AMPK, and TGF-β was observed, along with tissue-specific expression patterns in vascular, immune, and reproductive systems. These results provide a valuable multi-organ transcriptomic resource and offer new insights into the genetic mechanisms supporting high-altitude adaptation in yak.