title: Identification and expression analysis of 26 oncogenes of the receptor tyrosine kinase family in channel catfish after bacterial infection and hypoxic stress.
abstract: Receptor tyrosine kinases (RTKs) are high-affinity cell surface receptors for many polypeptide growth factors, cytokines and hormones. RTKs are not only key regulators of normal cellular processes, but are also involved in the progression of many types of tumors, and responses to various biotic and abiotic stresses. Catfish is a primary aquaculture species in the United States, while its industry is drastically hindered by several major diseases including enteric septicemia of catfish (ESC) that is caused by Edwardsiella ictaluri. Disease outbreaks are often accompanied by hypoxic stress, which affects the performance and survival of fish by reducing disease resistance. In this study, we identified 26 RTK oncogenes in the channel catfish genome, and determined their expression profiles after ESC infection and hypoxic stress. The 26 RTK genes were divided into four subfamilies according to phylogenetic analysis, including TIE (2 genes), ErbB (6 genes), EPH (14 genes), and INSR (4 genes). All identified RTKs possess a similar molecular architecture including ligand-binding domains, a single transmembrane helix and a cytoplasmic region, which suggests that these genes could play conserved biological roles. The expression analysis revealed that eight RTKs were significantly regulated after bacterial infection, with dramatic induction of insulin receptor genes including INSRb, IGF1Ra, and IGF1Rb. Upon hypoxic stress, EPHB3a, EGFR, ErbB4b, and IGF1Rb were expressed at higher levels in the tolerant catfish, while EPHA2a, EPHA2, TIE1 and INSRa were expressed at higher levels in the intolerant catfish. These results suggested the involvement of RTKs in immune responses and hypoxic tolerance.
authors.affiliation: Fish Molecular Genetics and Biotechnology Laboratory, Aquatic Genomics Unit, School of Fisheries, Aquaculture and Aquatic Sciences, and Program of Cell and Molecular Biosciences, Auburn University, Auburn, AL 36849, USA; College of Fisheries and Life Science, Dalian Ocean University, Dalian 116023, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Tian
authors.affiliation: Fish Molecular Genetics and Biotechnology Laboratory, Aquatic Genomics Unit, School of Fisheries, Aquaculture and Aquatic Sciences, and Program of Cell and Molecular Biosciences, Auburn University, Auburn, AL 36849, USA.
authors.forename: Jun
authors.initials: J
authors.lastname: Yao
authors.affiliation: Fish Molecular Genetics and Biotechnology Laboratory, Aquatic Genomics Unit, School of Fisheries, Aquaculture and Aquatic Sciences, and Program of Cell and Molecular Biosciences, Auburn University, Auburn, AL 36849, USA.
authors.forename: Shikai
authors.initials: S
authors.lastname: Liu
authors.affiliation: Fish Molecular Genetics and Biotechnology Laboratory, Aquatic Genomics Unit, School of Fisheries, Aquaculture and Aquatic Sciences, and Program of Cell and Molecular Biosciences, Auburn University, Auburn, AL 36849, USA.
authors.forename: Chen
authors.initials: C
authors.lastname: Jiang
authors.affiliation: Fish Molecular Genetics and Biotechnology Laboratory, Aquatic Genomics Unit, School of Fisheries, Aquaculture and Aquatic Sciences, and Program of Cell and Molecular Biosciences, Auburn University, Auburn, AL 36849, USA.
authors.forename: Jiaren
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Fish Molecular Genetics and Biotechnology Laboratory, Aquatic Genomics Unit, School of Fisheries, Aquaculture and Aquatic Sciences, and Program of Cell and Molecular Biosciences, Auburn University, Auburn, AL 36849, USA.
authors.forename: Yun
authors.initials: Y
authors.lastname: Li
authors.affiliation: Fish Molecular Genetics and Biotechnology Laboratory, Aquatic Genomics Unit, School of Fisheries, Aquaculture and Aquatic Sciences, and Program of Cell and Molecular Biosciences, Auburn University, Auburn, AL 36849, USA.
authors.forename: Jianbin
authors.initials: J
authors.lastname: Feng
authors.affiliation: Fish Molecular Genetics and Biotechnology Laboratory, Aquatic Genomics Unit, School of Fisheries, Aquaculture and Aquatic Sciences, and Program of Cell and Molecular Biosciences, Auburn University, Auburn, AL 36849, USA. Electronic address: liuzhan@auburn.edu.
authors.forename: Zhanjiang
authors.initials: Z
authors.lastname: Liu
mesh_terms: D000818:Animals; D020610:Edwardsiella ictaluri / Q000472:pathogenicity*; D000860:Hypoxia / Q000235:genetics*; D007059:Ictaluridae / Q000235:genetics*; D009857:Oncogenes; D010802:Phylogeny; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics*; D018805:Sepsis / Q000235:genetics* / Q000382:microbiology; D013312:Stress, Physiological
chemical_list: D020794:Receptor Protein-Tyrosine Kinases
keywords: Disease infection; Expression; Fish; Hypoxic stress; RTKs