Chronic cold exposure modulates genes related to feeding and immune system in Nile tilapia (Oreochromis niloticus). Issue 128 (September 2022)

• Record Type: Journal Article
• Authors: Dellagostin, Eduardo N.; Martins, Amanda W.S.; Blödorn, Eduardo B.; R. Silveira, Tony Leandro; Komninou, Eliza R.; Varela Junior, Antônio S.; Corcini, Carine D.; Nunes, Leandro S.; Remião, Mariana H.; Collares, Gilberto L.; Domingues, William B.; Giongo, Janice L.; Vaucher, Rodrigo A.; Campos, Vinicius F.
• Is Part Of: Fish & shellfish immunology. Issue 128(2022)
• Page Start: 269
• Page End: 278
• Publication Date: 2022-09
• Subjects: Nile tilapia -- Food intake -- Cytokines -- Gene expression -- Low temperatures; Fishes -- Immunology -- Periodicals; Shellfish -- Immunology -- Periodicals; Poissons -- Immunologie -- Périodiques; Crustacés -- Immunologie -- Périodiques; 571.9617
• DOI: 10.1016/j.fsi.2022.07.075
• Languages: English
• ISSNs: 1050-4648

Abstract

Abstract: Nile tilapia is the fourth most produced species in the global aquiculture panorama. This species requires water temperatures higher than 16 °C to grow and survive, and so, little is known about the effects of low temperatures on genes related to food intake and inflammatory responses. This study brought insights about the modulation of genes in different tissues of Nile tilapia chronically exposed to low temperatures. Thus, sixty animals were divided in two experimental groups: a control group in which the animals remained at the optimum temperature of 24 °C; and an exposed to cold group, in which a decrease in the water temperature was applied until reaching 15 °C. These conditions were maintained for 28 days. Blood samples were collected for flow cytometry analysis, while brain, spleen, liver, and kidney tissues were collected for total RNA extraction, followed by quantitative PCR (RT-qPCR). For genes related to feeding process pathway, it was observed an upregulation in pyy and a downregulation of npy and cart gene expression. Also, pro-inflammatory cytokine genes were modulated in the spleen, kidney and liver with a higher expression of il-1b and tnfα and a reduction in the il-8 and nf-κβ gene expressions in the group exposed to 15 °C. The fish exposed to cold presented higher serum cortisol levels than the ones from control group. The blood cell analysis showed a lower level of membrane fluidity and a higher DNA fragmentation and cell disruption in the group exposed to cold. These findings suggest an important effect of a stressful situation in the tilapia organism due to cold exposure. This study brings insights on tilapia wellbeing under low temperature stress. It can be a first step to understanding the appropriate way to cope with cold impacts on aquaculture. Graphical abstract: Image 1 Highlights: Chronic cold exposure reduces the specific growth rate of Nile tilapia. Food intake genes are modulated by low temperatures-induced fasting. Pro-inflammatory cytokine genes had their expression altered by cold exposure. Cold induces a higher DNA fragmentation and cell disruption parameters.