Transcriptome sequencing analysis on astaxanthin accumulation in muscle of Penaeus monodon

【Objective】 This study aimed to screen genes and signaling pathways that related to astaxanthin accumulated in muscle of Penaeus monodon,so as to provide basic data for elucidating the molecular mechanism of astaxanthin accumulation in muscle of shrimp.【Method】The muscle tissue were clipped from P. monodon individuals injected with astaxanthin(experimental group)and P. monodon individuals untreated(control group). After RNA extraction from the muscle of the experimental group and the control group,equal amounts were mixed to build cDNA libraries. Transcriptome sequencing was performed using Illumina HiSeq X Ten sequencer. After sequence assembly and annotation,differentially expressed genes(DEGs)were screened by DESeq. Then GO functional annotation analysis and KEGG signal pathway enrichment analysis were performed. The transcriptome data were confirmed by real-time quantitative PCR.【Result】The clean reads from experimental group and control group were 48415832 and 48532230,respectively. All clean reads were assembled into 20495 unigenes. There were 8761(42.75%),7658(37.37%),6933(33.83%),5584(27.25%)and 7238 (35.32%)Unigenes successfully annotated in Nr,Swiss-Prot,KOG,KEGG and GO databases respectively. Many Unigenes were mapped to 55 sub-categories of 3 terms of biological process,cellular component and molecular function in GO database. After DESeq screening,a total of 1468 DEGs were identified in the experimental group and the control group,of which 1209 DEGs were up-regulated and 259 DEGs were down-regulated in the control group. The genes related to astaxanthin accumulation in muscle were cytochrome b5(CYB5),cytochrome P450(CYP450),glucosyl/glucuronosyl transferase(UDPGT),kelch-like protein(KLHL),ATP-binding cassette transporter and lipoprotein receptor (ABCT),lipid protein receptor gene(LipR),lipase and caspase 3(CASP3),et al. The GO function categories with the most DEGs was polysaccharide catabolic process. The most enriched KEGG signal pathway was signal transduction.【Conclusion】 The DEGs(including CYP450,CYB5, ABCT,LipR,KLHL,UDPGT,CASP3 and lipase)and signal pathways(such as signal transduction,transport and catabolism,endocrine system,coenzyme factor and vitamin metabolism)are found to be related to astaxanthin accumulation in P. monodon. In the future,the function of these DEGs using techniques such as in situ hybridization,prokaryotic expression will be analyzed to further reveal the molecular mechanism of astaxanthin accumulation in muscle of shrimp.