Transcriptome profiling of grass carp (Ctenopharyngodon idellus) infected with Aeromonas hydrophila.

Aeromonas hydrophila is the causative pathogen of intestinal hemorrhage which has caused great economic loss in grass carp aquaculture. In order to understand the immunological response of grass carp to infection by A. hydrophila, the transcriptomic profiles of the spleens from infected and non-infected grass carp groups were obtained using HiSeq™ 2500 (Illumina). An average of 63 million clean reads per library was obtained, and approximately 80% of these genes were successfully mapped to the reference genome. A total of 1591 up-regulated and 530 down-regulated genes were identified. Eight immune-related categories involving 105 differently expressed genes were scrutinized. 16 of the differently expressed genes involving immune response were further validated by qRT-PCR. Our results provide valuable information for further analysis of the mechanisms of grass carp defense against A. hydrophila invasion.