title: Acute phase response in Chinese soft-shelled turtle (Trionyx sinensis) with Aeromonas hydrophila infection.
abstract: Chinese soft-shelled turtle (Trionyx sinensis) is an important culture reptile. However, little is known about its acute phase response (APR) caused by bacteria. Serum amyloid A (SAA) is a major acute phase protein (APP). In this study, a turtle SAA homologue was identified and described in reptiles. The full-length cDNA of turtle SAA was 554 bp and contained a 381 bp open reading frame (ORF) coding for a protein of 127 aa. Similar to other known SAA genes, the turtle SAA gene contained three exons and two introns. The promoter region of turtle SAA gene contained the consensus binding sites for nuclear factor (NF)-κB and c-Rel. The turtle SAA amino acid sequence shared the highest identity to avian SAA sequences. Meantime, we present the first systematic study with expression levels of five genes encoding APPs in immune response caused by Aeromonas hydrophila infection. After infection, turtle SAA mRNA was induced in liver at 8h, then increased more than 1200-fold at 2d; in spleen and kidney, the SAA mRNAs were also induced during 8h-7d, but the level was far lower than that in the liver. The complement 3 (C3), fibrinogen-gamma chain (Fb-G) and cathepsin L (CathL) mRNAs were increased in liver at 2d, whereas the albumin (ALB) mRNA was significantly decreased during 8h-7d. Our studies suggest that the APR in turtle with A. hydrophila infection is similar to that in mammals, and SAA is a major indicator of bacterial infection, especially at early stage, in reptiles. Additionally, the different expression patterns of five APP genes observed in present studies could provide clues for understanding the innate immune mechanisms in the APR of reptiles.
authors.affiliation: Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China.
authors.forename: Xiuxia
authors.initials: X
authors.lastname: Zhou
authors.forename: Lu
authors.initials: L
authors.lastname: Wang
authors.forename: Hong
authors.initials: H
authors.lastname: Feng
authors.forename: Qionglin
authors.initials: Q
authors.lastname: Guo
authors.forename: Heping
authors.initials: H
authors.lastname: Dai
mesh_terms: D000209:Acute-Phase Proteins / Q000235:genetics / Q000276:immunology; D000210:Acute-Phase Reaction / Q000662:veterinary*; D016980:Aeromonas hydrophila; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D016905:Gram-Negative Bacterial Infections / Q000276:immunology / Q000662:veterinary*; D007113:Immunity, Innate; D008969:Molecular Sequence Data; D010802:Phylogeny; D011401:Promoter Regions, Genetic; D030162:Reptilian Proteins / Q000235:genetics / Q000276:immunology; D000685:Serum Amyloid A Protein / Q000235:genetics / Q000276:immunology; D014426:Turtles / Q000276:immunology*
chemical_list: D000209:Acute-Phase Proteins; D030162:Reptilian Proteins; D000685:Serum Amyloid A Protein