Abstract: Birds need high-efficiency mechanism of blood glucose regulation to get energy for flying. SLC2A4 and its coding protein Glucose transporter type 4 (GLUT4) play a major role for glucose transport in skeletal muscle cells when birds fly. In this study, all of the 17 avian SLC2A4 sequences were got from GenBank, results showed that the sequences had high variation in the length and base composition. It also showed all the GLUT4 were hydrophilia and had many O-glycosylation sites, but had no transmembrane structure, and signal peptide sites were located in 11-57 site of GLUT4. Selection pressure analysis showed that it was positive selection in Carinatae, but negative selection in Ratitae. Using maximum likelihood (ML) and Bayesian inference (BI) methods based on the GLUT4, both of the trees were highly similar topologies and high bootstrap proportion values. The phylogenetic analysis showed that Struthioniformes, Apterygiformes and Tinamiformes formed together, then grouped with Galliformes, Anseriformes, Columbiformes and Passeriformes. Our results may provide useful information about the evolution of SLC2A4 in birds.

Key words: SLC2A4, GLUT4, sequence characterization, evolutionary rate, phylogeny