Transcriptome analysis reveals differential gene expression associated with white spot syndrome virus resistance in the shrimp Litopenaeus vannamei fed on functional diets

Abstract

The White Spot Syndrome Virus (WSSV) is one of the most lethal pathogens in the shrimp aquaculture industry. Therefore, several studies have focused on developing alternatives to reduce its negative effects. Different functional feeds have been probed to enhance survival against WSSV infection by improving shrimp health condition. This study evaluated the effect of functional feeds on differential gene expression and their association with WSSV resistance in shrimp Litopenaeus vannamei. A total of seven diets were used to fed shrimp during 28 days of trial: a reference feed (Ref), five functional feeds including a synbiotic (Syn), seaweeds extract (Alg), vitamin C (VitC), β-glucan (Bglu), turmeric and maca meal (TuMa), and a feed with deficiency of highly unsaturated fatty acids (L-Hufa). At the end of the feeding period, shrimp were sampled for transcriptomic analysis, and a WSSV challenge was performed to evaluate virus replication and survival of shrimp. After 96 h post-infection (hpi), the higher survival rates were observed in shrimp fed with TuMa and Alg diets (WSSV-resistant), 46% and 35% respectively, meanwhile shrimp fed Ref, Vit C, and Bglu diets (WSSV-susceptible) showed 100% mortality at 84 hpi. According to WSSV replication kinetics, at 72 hpi, viral copies highly increased for Ref and Syn treatments (> 8 × 107 copies/ng DNA), and specimens fed L-Hufa resulted in the lowest number of viral copies among treatments (2.6 × 106 copies/ng DNA). Up-regulated genes in the WSSV-resistant shrimp group were mostly related to translation (ribosomal proteins), energetic production (glyceraldehyde-3-phosphate dehydrogenase, hydroxyacyl-coenzyme A dehydrogenase, malate dehydrogenase, NADH dehydrogenase, and ATP synthase subunit b), antioxidant activity (glutathione peroxidase and glutathione S-transferase), and immune response (toll receptor, ubiquitin-conjugating enzyme E2, C-type lectin, ctenidin-1 and acanthoscurrin-2). The transcriptomic response of shrimp fed with TuMa and Alg feeds shown DEGs potentially related to WSSV resistance.