Effects of microplastics on gene expression to nonspecific immune system in pacific white shrimp (Litopenaeus vannamei).

Abstract

Microplastics pollution effects are increasingly observed as new studies emerge in different ecosystem and organismal levels. It is becoming clear that exposure to different types of microplastic can impair the nonspecific immune system of crustaceans. Therefore, this study investigated the impact of high-density polyethylene microplastic particles (HDPE-MP) in feed on nonspecific immune system gene expression of Pacific white shrimp (Litopenaeus vannamei). The LC50 at day 28 of HDPE-MP ingestion was 3.074% w/w of food. Superoxide dismutase (SOD) and the Glutathione peroxidase (GPx) gene were upregulated significantly in groups supplemented with 0.1 and 0.5% of HDPE-MP and then down-regulated significantly after ingested for extended period of time. Lysozyme (LYZ) gene was down-regulated significantly in all treatment groups after 14 days of exposure. Significant histopathological changes in the hepatopancreas such as interstitial hemocytic infiltration, epithelium hyperplasia, tubular deformity, nodule formation, and melanization were observed in the HDPE-MP treatment groups. The severity of each lesion increased, corresponding to the increasing concentration of HDPE-MP. Ingestion of HDPE-MP contaminated feed can interfere with expression of major antioxidant and anti-bacterial genes and damage the hepatopancreas in Pacific white shrimp.