Provincial Institute of Fisheries-Isabela State University-Roxas Campus, Roxas, Isabela
DA-Bureau of Fisheries and Aquatic Resources Region 02 Government Center, Carig, Tuguegarao City, Philippines
Corresponding author
antonioleonjr88@gmail.com
Emma L. Ballad2
Marites Ramos-Castro1
Isagani P. Angeles Jr.1
Mary Joy Libatique-Asprec1
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.