Comparative Analysis of Key Transcription Factors Involved in Development in Sea Lamprey (Petromyzon marinus) through Systematic Mining of Lamprey Gene Expression Dataset.

Transcription factors (TFs), key regulators for gene expression, play varied yet crucial roles throughout cellular polarization, migration, proliferation, differentiation and apoptosis. An important function of TFs is acting in embryogenesis and organogenesis. To identify the candidate TFs in the progression of lamprey early embryogenesis, datasetGSE76037 was downloaded from the Gene Expression Omnibus (GEO) database and an integrated bioinformatic analysis was performed. Our findings revealed a total of 152 TFs in the dataset. The function enrichment analysis showed that these genes were mainly enriched in transcription from RNA polymerase II promoter, cell differentiation, embryonic digestive tract morphogenesis and so on. Hierarchical clustering analysis suggested the expression of TFs was significantly different during early embryogenesis. Moreover, volcano plots and Venn diagrams analysis identified 36 key TFs, which were considered to play an important role during embryogenesis. The weighted correlation network analysis (WGCNA) was constructed and the Pearson correlation coefficient was performed, indicating these TFs might involve in early development of lamprey germline by synergistically regulating each other. The result was confirmed by real-time polymerase chain reaction and Western blotting analysis. In conclusion, differentially expressed genes identified in the present study help us understand the molecular mechanisms underlying the lamprey embryogenesis and provide candidate TFs for further study of vertebrate embryonic development.

Identification and evolution of transcription factors RHR gene family (NFAT and RBPJ) involving lamprey (Lethenteron reissneri) innate immunity.

Nuclear factor of activated T cells (NFAT) and recombination signal binding protein (RBP) belong to the family of Rel homology region (RHR) transcription factors which regulate the expression of genes involved in different aspects of the immune response. To gain insights into the evolution and characterisation of RHR genes in lampreys, a jawless vertebrate, four RHR genes, including nuclear factor of activated T cells (NFAT) and recombination signal binding protein for immunoglobulin kappa J region (RBPJ), have been identified and cloned from the lamprey (Lethenteron reissneri) database. Evolutionary relationships of NFAT and RBPJ genes among different species were determined through molecular phylogenetic analysis. Motif, genetic structure, and tertiary structure analyses showed that NFATs and RBPJ are conserved and contain RHD and IPT domains. Moreover, synteny analysis showed that the neighbourhood genes of Lr-NFATs and Lr-RBPJ have undergone significant changes compared to jawed vertebrates. Real-time quantitative results demonstrated that the RHR gene family plays a significant role in immune defence. This study provides a new understanding of the origin and evolution of the RHR gene family in different species.