Institute of Aquaculture, College of Fisheries and Ocean Sciences, University of the Philippines Visayas, Miagao 5023, Iloilo, Philippines
Institute of Bioinformatics and Systems Biology, College of Engineering Bioscience, National Yang Ming Chiao Tung University, Hsinchu, Taiwan
Corresponding author
reamae.omeccas22@gmail.com
This study investigated the effects of dietary vitamin C (vitC) and lipid on the expression of immune-related genes in Litopenaeus vannamei postlarvae subjected to thermal stress, with water temperature fluctuating from 27.0 ± 1.1 to 34.0 ± 1.8 °C for 15 days. Three experimental diets were formulated containing two different levels of vitC (1 and 3 g kg -1) and lipid (17 and 34 g kg -1). Significantly higher total hemocyte count (9.63 × 105 ± 3.28 × 105 cells ml -1) was observed in shrimp fed 3 g kg -1 vitC and 34 g kg -1 lipid diets. Using real-time quantitative polymerase chain reaction and the comparative 2-ΔΔCt method, the dietary vitC level of 3 g kg -1 significantly upregulated heat shock protein 90 (HSP90), heat shock protein 70 (HSP70), anti-lipopolysaccharide factor (ALF), crustin, and the Prophenoloxidase (proPO) system. Meanwhile, the dietary lipid level of 34 g kg -1 resulted in a significant upregulation of HSP90 and penaeidin 2 (PEN 2) genes. Regarding the growth and survival indices of the shrimps fed the formulated diets, no significant differences (P > 0.05) were observed. In conclusion, increased dietary supplementation of vitC (3 g kg -1 diet) and lipid (34 g kg -1 diet) upregulated the immune-related genes, enhancing the immunity of shrimps during thermal stress.