Project description:Meagre (Argyrosomus regius) belongs to the family Sciaenidae and is a promising candidate for Mediterranean aquaculture diversifcation. As a relatively recent species in aquaculture, the physiological consequences of the immune system activation in meagre are understudied. Spleen, as a primary lymphoid organ has an essential role in meagre immune and inflammatory responses. In this study, we have evaluated the in vivo effects of lipopolysaccharide (LPS) on the spleen transcriptome of meagre by RNA-seq analysis at 4 and 24 h after injection. The assembled transcripts were assigned to immunological processes. At 24 h, the number and type of differential immune-related genes regulated by LPS was higher than at 4 h. However, at 4 h the upregulation of immune-related genes was greater. Several genes related to the innate immune response were upregulated including tolllike receptor 5, and multiple interferons and interferon-related proteins. In the present work, it was shown that several chemokines and chemokine ligands (e.g. cxcl10, ccl21) as well as cytokines (e.g. il1b, il12, il27) were overexpressed as a result of LPS injection, supporting their role as mediators of the innate and adaptive immune response. KEGG analysis found that LPS-stimulated immune responses mainly involve cytokine and protein-protein interactions involved in pathogen response. Specifcally, genes involved in the MHCI and MHCII pathways were induced as early as 4 h post LPS injection. These results will help to understand the pathogenesis and host defense system in meagre.
Project description:In aquaculture, meagre (Argyrosomus regius), it still produced on a small scale, nevertheless it is a species with great potential to expand due to its beneficial traits both for production and consumption. The development of new functional diets for this species that can promote both growth and health is an important step towards the increase of its production. Studying fish health and nutrition status can be complex and cause additional stress to the fish, and often require animal sacrifice. Therefore, it becomes important to find proper techniques and biomarkers that allow a better measurement of the effects of new diets and at the same time are practical to apply in an aquaculture setting. Using non-lethal measurements to evaluate fish health and welfare has generated interest as it allows for less animal sacrifice and reduced production losses. This type of analysis includes parameters from samples of blood, mucus, skin and faeces, which are important tools for monitoring fish health and welfare. In this study, a nutritional challenge was performed for 7 weeks with juvenile meagre, where three diets were tested, a control diet (55.1 % of fish meal, FM, control), a challenging diet (15% FM, challenge) and an extremely challenging diet (5% FM, extreme). The main objective was to identify candidate minimally invasive biomarkers of malnutrition in blood plasma and skin mucus.