title: Microarray analysis of gene expression in the blue catfish liver reveals early activation of the MHC class I pathway after infection with Edwardsiella ictaluri.
abstract: The acute nature of disease outbreaks in aquaculture settings has served to emphasize the importance of the innate immune response of fish for survival and led to the recent identification and characterization of many of its components. Catfish, the predominant aquaculture species in the United States, is an important model for the study of the teleost immune system. However, transcriptomic-level studies of disease-related gene expression in catfish have only recently been initiated, and understanding of immune responses to pathogen infections is limited. Here, we have developed and utilized a 28K in situ oligonucleotide microarray composed of blue catfish (Ictalurus furcatus) and channel catfish (Ictalurus punctatus) transcripts. While channel catfish accounts for the majority of commercial production, the closely related blue catfish possesses several economically important phenotypic traits. Microarray analysis of gene expression changes in blue catfish liver after infection with Gram-negative bacterium Edwardsiella ictaluri indicated the strong upregulation of several pathways involved in the inflammatory immune response and potentially in innate disease resistance. A multifaceted response to infection could be observed, encompassing the complement cascade, iron regulation, inflammatory cell signaling, and antigen processing and presentation. The induction of several components of the MHC class I-related pathway following infection with an intracellular bacterium is reported here for the first time in fish. A comparison with previously published expression profiles in the channel catfish liver was also made and the microarray results extended by use of quantitative RT-PCR. Our results add to the understanding of the teleost immune responses and provide a solid foundation for future functional characterization, genetic mapping, and QTL analysis of immunity-related genes from catfish.
authors.affiliation: The Fish Molecular Genetics and Biotechnology Laboratory, Department of Fisheries and Allied Aquacultures, Program of Cell and Molecular Biosciences, Aquatic Genomics Unit, Auburn University, Auburn, AL 36849, USA.
authors.forename: Eric
authors.initials: E
authors.lastname: Peatman
authors.forename: Jeffery
authors.initials: J
authors.lastname: Terhune
authors.forename: Puttharat
authors.initials: P
authors.lastname: Baoprasertkul
authors.forename: Peng
authors.initials: P
authors.lastname: Xu
authors.forename: Samiran
authors.initials: S
authors.lastname: Nandi
authors.forename: Shaolin
authors.initials: S
authors.lastname: Wang
authors.forename: Benjaporn
authors.initials: B
authors.lastname: Somridhivej
authors.forename: Huseyin
authors.initials: H
authors.lastname: Kucuktas
authors.forename: Ping
authors.initials: P
authors.lastname: Li
authors.forename: Rex
authors.initials: R
authors.lastname: Dunham
authors.forename: Zhanjiang
authors.initials: Z
authors.lastname: Liu
mesh_terms: D000210:Acute-Phase Reaction / Q000276:immunology; D000818:Animals; D002397:Catfishes / Q000235:genetics* / Q000276:immunology* / Q000382:microbiology; D015536:Down-Regulation; D020610:Edwardsiella ictaluri / Q000276:immunology; D004756:Enterobacteriaceae Infections / Q000235:genetics* / Q000276:immunology; D029941:Fish Proteins / Q000235:genetics / Q000378:metabolism; D005786:Gene Expression Regulation; D015395:Histocompatibility Antigens Class I / Q000235:genetics*; D007059:Ictaluridae / Q000235:genetics / Q000276:immunology; D008099:Liver / Q000378:metabolism / Q000382:microbiology*; D020411:Oligonucleotide Array Sequence Analysis; D017510:Protein Folding; D011499:Protein Processing, Post-Translational; D021381:Protein Transport; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D015203:Reproducibility of Results
chemical_list: D029941:Fish Proteins; D015395:Histocompatibility Antigens Class I; D012333:RNA, Messenger