Metatrancriptomic analysis from the Hepatopancreas of adult white leg shrimp ( Litopenaeus vannamei)

White leg shrimp (Litopenaeus vannamei) is a widely cultured shellfish in coastal areas of the Pacific and is considered one of the dominant crustaceans in aquaculture, globally. There is currently no information regarding the functional role of the microbiome of L. vannamei. In this study Next Generation Sequencing techniques were used to generate the metatranscriptome of the hepatopancreas from adult individuals of this species. The functional role of the microbiome showed that the most represented bacterial phylum consisted of Proteobacteria, Firmicutes and Actinobacteria, in which several bacterial classes produce different sets of hydrolytic enzymes. The most represented functions in the microbiome were related to the metabolism of proteins, amino acids, carbohydrates and lipids. These systems were also highly represented in L. vannamei. This response suggests that the nutrient absorption involves the joint participation of the host and the microbiome. A similar behavior was observed in abiotic stress related genes in L. vannamei and the microbial communities. There was a high representation in both systems, suggesting that the host-microbiome has adapted to the environmental fluctuations. Pathogens were found in this study in low titers, which are common in marine organisms; and several mechanisms that participate in the pathogenic response of L. vannamei were identified such as: proteolytic enzymes and cell communication mechanisms. Over a thousand genic microbial products were identified in the metatranscriptome of L. vannamei including the presence of several genes related to metabolic functions, stress and antibiotic resistance. This study provides evidence of the microbiome interactions in L. vannamei during the culture of this species and the different factors that could affect the microbial composition and gene expression.