Proteomic analysis of eleven tissues in the Chinese giant salamander (Andrias davidianus).

The Chinese giant salamander (Andrias davidianus, CGS) is the largest extant amphibian species in the world. Global quantitative proteome analysis of multiple tissues would indicate tissue-specific physiological processes and clarify the function of each protein from a whole-organism perspective. This study performed proteome analysis of eleven tissues collected from adult CGSs using iTRAQ coupled with LC-MS/MS technology. Based on the predicted protein database from previously obtained CGS transcriptome data, 2153 proteins were identified for subsequent analysis. A weighted gene co-expression network analysis (WGCNA) clustered 2153 proteins into 17 co-expressed modules, which will be useful for predicting the functions of unannotated proteins. The protein levels of molecular complexes with housekeeping functions, such as ribosomes, spliceosomes and mitochondrial respiratory chain complexes, were tightly regulated in different tissues of the CGS, as they are in mammalian tissues. Transcription regulator, pathway and bio-functional analysis of tissue-specific proteins showed that highly expressed proteins largely reflected the physiological functions of specific tissues. Our data, as an initial atlas of protein expression of an amphibian species, will be useful for further molecular biology research on CGS.