Classfication and Evolution of HLH Family Members in Poultry Genome

Based on the amino acid sequence of bHLH-zip motif in SREBP-1 and SREBP-2 in Landes goose obtained by gene cloning, the sequences of HLH family members in poultry genome were screened in the Protein Databases of NCBI. The classification and evolution of HLH protein family in poultry genome were analyzed. HLH protein family in poultry genome are divided into five groups (A, B, C, D and E) according to the sequence features of bHLH domain. The result of phylogenetic development indicates the sequences of HLH family members in poultry genome also gather into five groups, and this grouping is generally consistent with the classification by sequence features. Group B diverges from other groups firstly, and the divergent time of group A is the latest. Groups A and D have closer genetic relationship, and groups C and E have closer phylogenetic relationship.