Phylogenetic Analysis of C Type Lectin From Toxocara Canis Infective Larvae and Comparison With the C Type Lectin Family in the Immune System of Mouse and Human

Background: c type lectin (ctl) family is a type of calcium-dependent proteins found in vertebrates and invertebrates. the objective of this study was to perform a comparative analysis and phylogenetic inferring for understanding the similarities and differences of carbohydrate recognition domain (crd) domain of toxocara canis ctl and other nematodes, and similar c type lectin involved in the immune system of mouse and human as their host. methods: the female t. canis was retrieved from the 2-6 months puppies (department of parasitology, faculty of veterinary medicine, university of tehran, 2015). to collect t. canis eggs, the worms were cultured for 5 d until they were embryonated. the hatching process was accelerated for collecting the stage 2 larvae, and the larvae were cultured for a week. a cdna library was made from the total mrna of t. canis infective larvae. the pcr amplification for c type lectin gene was performed and the amino acids were analyzed using the alignment method and the construction of phylogenetic tree. results: the suspension sample maintained at 30 ºc for four weeks could embryonate 90%-100% of eggs. t. canis ctl gene was 657 bp in length and encoded a protein with 219 amino acids. the ctl of species of strongylida order were closely placed in the tree, whereas the members of ascaridida orders were located in a separate branch. high levels of similarity (36%-44%) and conservation of c type lectin from t. canis with mouse and human c type lectins. its c type lectin showed a higher similarity with asialoglycoprotein receptor (asgpr), macrophage lectin, dendritic cell-specific intercellular adhesion molecule 3-grabbing nonintegrin (dc-sign), mincle receptor of mouse and human. conclusion: analysis of crd domain of c type lectin protein could make a better understanding of their role in the interaction of nematode parasite with their hosts.