Identification and characterization of tyrosine kinases in anole lizard indicate the conserved tyrosine kinase repertoire in vertebrates.

The tyrosine kinases (TKs) play principal roles in regulation of multicellular aspects of the organism and are implicated in many cancer types and congenital disorders. The anole lizard has recently been introduced as a model organism for laboratory-based studies of organismal function and field studies of ecology and evolution. However, the TK family of anole lizard has not been systematically identified and characterized yet. In this study, we identified 82 TK-encoding genes in the anole lizard genome and classified them into 28 subfamilies through phylogenetic analysis, with no member from ROS and STYK1 subfamilies identified. Although TK domain sequences and domain organization in each subfamily were conserved, the total number of TKs in different species was much variable. In addition, extensive evolutionary analysis in metazoans indicated that TK repertoire in vertebrates tends to be remarkably stable. Phylogenetic analysis of Eph subfamily indicated that the divergence of EphA and EphB occurred prior to the whole genome duplication (WGD) but after the split of Urochordates and vertebrates. Moreover, the expression pattern analysis of lizard TK genes among 9 different tissues showed that 14 TK genes exhibited tissue-specific expression and 6 TK genes were widely expressed. Comparative analysis of TK expression suggested that the tissue specifically expressed genes showed different expression pattern but the widely expressed genes showed similar pattern between anole lizard and human. These results may provide insights into the evolutionary diversification of animal TK genes and would aid future studies on TK protein regulation of key growth and developmental processes.