Molecular evolution of the transcription factor PRDM genes and expression profiles in response to stimulations and spinal cord injury repair in lamprey (Lethenteron reissneri).

Positive regulatory domain member (PRDM) family proteins play important roles in nervous system development, neural stem cell proliferation and differentiation, and central nervous system inflammation. The unique evolutionary position of the lamprey (Lethenteron reissneri) as one of the oldest jawless vertebrates makes it an ideal animal model for understanding vertebrate evolution. Nevertheless, the evolutionary characteristics of PRDM genes have not yet been demonstrated in lampreys. In this study, we identified PRDM1, 4, 5, 8, 12, 14, and 15 genes in the lamprey genomes and also investigated their evolutionary relationships through phylogenetic analysis. The characterization of PRDM genes appears to be conserved among vertebrates, as indicated by protein structural domain, motif, and 3D structure analysis. Genomic synteny analysis revealed that lamprey PRDM neighbor genes are significantly different from those of jawed vertebrates. Real-time quantitative results demonstrate that the PRDM gene family may be involved in immune defense and spinal cord injury (SCI) repair. This study not only enriches the understanding of PRDM gene evolution but also provides new clues for the Lr-PRDMs' roles in immune defense and SCI.