Tilapia is an important freshwater aquaculture species worldwide. In recent years, streptococcal diseases have severely threatened development of tilapia aquaculture, while effective prevention and control methods have not yet been established. In order to understand the immunological response of tilapia to infection by Streptococcus agalactiae (S. agalactiae), this study employed Solexa/Illumina RNA-seq and digital gene expression (DGE) technology to investigate changes in the tilapia transcriptome before and after S. agalactiae infection.
Researchers at the Chinese Academy of Fishery Sciences obtained 82,799 unigenes (mean size: 618 bp) using de novo assembly. Combined with DGE technology, transcriptomic changes in tilapia before and after bacteria challenging were examined. A total of 774 significantly up-regulated and 625 significantly down-regulated unigenes were identified, among which 293 were mapped to 181 signaling pathways including 17 immune-related pathways involving 65 differentially expressed genes. This comparative study of the tilapia transcriptome before and after S. agalactiae infection identified important differentially-expressed immune-related genes and signaling pathways that will provide useful insights for further analysis of the mechanisms of tilapia defense against S. agalactiae infection.
- Zhang R, Zhang LL, Ye X, Tian YY, Sun CF, Lu MX, Bai JJ. (2013) Transcriptome profiling and digital gene expression analysis of Nile tilapia (Oreochromis niloticus) infected by Streptococcus agalactiae. Mol Biol Rep [Epub ahead of print]. [abstract]