The Evolution Analysis Of Intelectin Gene Family

Intelectin is a recently described animal lectin recognizing galactofuranosyl residues included in cell walls of various microorganisms, and play a role in innate immunity. Although Amphioxus and catfish intelectin can function as agglutinin, yet the underlying mechanismsof the lectin activity was poorly understood. The various intelectin functions among different species rasies the significance of the evolution mechanisms of intelectin gene family. In this study, we performed some bioinformatics and systemic phylogenic analysis using intelectin sequences from various species to explore the function and evolution of this gene family. Multiple alignments showed inteletins was highly conserved among different species. A FReD in N-terminus was predicted by software, while a conserved region in C-terminus matched no reported domains of Protein Data Bank (PDB). Motif predication and exon analysis both exhibited that the region (motif1,3,4,2,5,10,7,6) was highly conserved in nucleotide and amino acid levels. Taken together, we separate the full length of intelectin into three regions and constructed the phylogenetic tree respectively. The three trees share the same evolution tendency but with some difference in detailed, indicating that the three regions had unique evolution processes. The putative signal peptide and N-glycosylation site vary considerably among different species, especially between vertebrate and invertebrate animals, suggesting the multiple functions of Intelctin gene family in the original stage. Furthermore, we also conducted phylogenic analysis, using intelectins from species with multiple copies. Additionally, we cloned an amphioxus homolog, Amphi86230, coding302amino acid and constructed a recombinant vector pET29b-Amphi86230expressed in E. coli system. Our work provide new evidence leading to a profound understanding of the evolution and function of intelectin gene family.