Phylogenomics Based on Transcriptome Data Provides Evidence for the Internal Phylogenetic Relationships and Potential Terrestrial Evolutionary Genes of Lungfish

The evolutionary relationships of lungfish can provide crucial information on the transition from Sarcopterygii to tetrapods. Phylogenomics is necessary explore accurate internal phylogenetic among all species. In context lack genome-wide genetic for Protopterus amphibious , we are first systematically report transcriptome P. amphibius and these sequences be used enrich lungfish. Meanwhile, also found significant differences in expression levels 3,189 genes between lung heart . Based phylogenomics, 1,094 shared orthologous were identified then applied reconstruct structure reconstructed evidence that sister group terrestrial vertebrates Neoceratodus forsteri most primitive Moreover, divergence time other species 186.11 195.36 MYA. Finally, 43 protein metabolism-related, stress response-related, skeletogenesis-related have undergone positive selection fast evolution N. We suspected possibly helped ancient fish adapt new environment ultimately contributed its spreading land.