title: Nutritional impacts on gene expression in the surface mucosa of blue catfish (Ictalurus furcatus).
abstract: Short-term feed deprivation is a common occurrence in both wild and farmed fish species, due to reproductive processes, seasonal variations in temperature, or in response to a disease outbreak. Fasting can have dramatic physiological and biological consequences for fish, including impacts on mucosal immunity which can, in turn, change host susceptibility to pathogens. Culture and selection of blue catfish (Ictalurus furcatus) has gained importance as the production of a channel catfish×blue catfish (Ictalurus punctatus×I. furcatus) hybrid has increased in the Southeast US. Following a recent examination of fasting-induced impacts on mucosal immunity in channel catfish, here we utilized Illumina-based RNA-seq expression profiling to compare changes in blue catfish gill and skin after a brief (7 day) period of fasting. Transcriptome sequencing and de novo assembly of over 194 million 100 base-pair transcript reads was followed by differential expression analysis. Fasting altered a total of 530 genes in the surface mucosa, including genes regulating the immune response, energy metabolism, mucus production, cellular cytoskeletal structure, cell proliferation, and antioxidant responses. In particular, fasting perturbed arginine synthesis and metabolism pathways in a manner likely altering macrophage activation states and immune readiness. Our findings highlight key mediators of the critical interaction between nutrition and immunity at points of pathogen adherence and entry.
authors.affiliation: School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL 36849, USA.
authors.forename: Chao
authors.initials: C
authors.lastname: Li
authors.affiliation: United States Department of Agriculture, Agricultural Research Service, Stuttgart National Aquaculture Research Center, Stuttgart, AR 72160, USA.
authors.forename: Benjamin H
authors.initials: BH
authors.lastname: Beck
authors.affiliation: School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL 36849, USA. Electronic address: peatmer@auburn.edu.
authors.forename: Eric
authors.initials: E
authors.lastname: Peatman
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D001120:Arginine / Q000096:biosynthesis* / Q000235:genetics; D002397:Catfishes / Q000502:physiology*; D048708:Cell Growth Processes / Q000235:genetics; D004734:Energy Metabolism / Q000235:genetics; D005215:Fasting / Q000502:physiology*; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation / Q000502:physiology; D005880:Gills / Q000502:physiology*; D018928:Immunity, Mucosal / Q000235:genetics; D008262:Macrophage Activation / Q000235:genetics; D009092:Mucous Membrane / Q000502:physiology*; D009747:Nutritional Physiological Phenomena / Q000235:genetics; D012879:Skin Physiological Phenomena
chemical_list: D000975:Antioxidants; D001120:Arginine
keywords: Feed deprivation; Fish; Flavobacterium columnare; Immune response; Mucosal; RNA-seq