Transcriptomics analysis of the response of green mud crabs S. paramamosain to dietary DHA/EPA

To explore the regulation mechanism of dietary DHA/EPA on the metabolism pathway in S. paramamosain, Illumina HiSeq sequencing platform was used to sequence the hepatopancreas of green mud crab fed diets with 0.6 (D1) and 2.3 (D3) ratio of DHA/EPA at 7% dietary lipid. A total of 38.93 Gb of raw data was obtained. After assembly and redundancy removal, 105733 Unigenes were obtained, the mean length, N50 and percent of GC of Unigenes were 1177 bp, 2368 and 44.51%, respectively. 105733 CDS were discovered, the N50 and percent of GC of CDS were 1512 and 51.88%. 38.67% of sequenced genes were annotated in Litopenaeus vannamei. 175 genes (78 up-regulated and 97 down-regulated, D1 vs D3) were characterized as the most differentially expressed genes between green mud crab fed diets with 0.6 and 2.3 ratio of DHA/EPA. There were 10 significantly enriched signaling pathways, including nitrogen metabolism, ribosome, thermogenesis, glutamatergic synapse, GABAergic synapse, parkinson disease, necroptosis, arginine biosynthesis, oxidative phosphorylation and alanine, aspartate and glutamate metabolism. In conclusion, amino acid metabolism, energy metabolism and metabolism related to immune response were processed to ensure function and energy supply and reduce/restore the inflammatory response caused by low energy intaking, when dietary DHA/EPA increased from 0.6 to 2.3 at 7% lipid.