Comprehensive visceral transcriptome profiling of three pig breeds along altitudinal gradients in Yunnan.

High-altitude hypoxia acclimatization requires comprehensive physiological regulation in highland immigrants, yet the genetic mechanisms remain unclear. Yunnan's vertical zoning with pig breeds distributed across varying elevations provides an excellent model for investigating hypoxic adaptation. Here, we examined three indigenous Yunnan pig breeds: Diannan small-ear pigs (DSE, 500 m), Baoshan pigs (BS, 1500 m), and Diqing Tibetan pigs (DT, 3200 m). Using PacBio Iso-Seq, we obtained comprehensive full-length transcriptomes from five tissues (heart, kidney, liver, lung, and spleen), identifying 51,774 transcripts, including 34,813 novel ones, 74,843 Alternative Splicing (AS) events across 10,686 AS genes and pinpointed five actin-binding genes through weighted gene co-expression network analysis (WGCNA). Our research significantly improved porcine genome annotation and provided a high-quality transcriptome resource for investigating the genetic mechanisms of high-altitude hypoxia adaptation. This work lays a solid foundation for future studies in genetics, evolutionary biology, and environmental adaptation.