The identification, characterization, and expression analysis of genes relevant to immune responses in Atlantic cod (Gadus morhua)

Feng, Charles Yu (2009) The identification, characterization, and expression analysis of genes relevant to immune responses in Atlantic cod (Gadus morhua). Masters thesis, Memorial University of Newfoundland.

[English] PDF - Accepted Version Available under License - The author retains copyright ownership and moral rights in this thesis. Neither the thesis nor substantial extracts from it may be printed or otherwise reproduced without the author's permission. Download (26MB)

Abstract

The Atlantic cod (Gadus morhua) is an important species for global fisheries and aquaculture industries. A thorough knowledge of the genes and molecular pathways involved in Atlantic cod immune responses will likely lead to the development of new diagnostics, vaccines, and other methods of combating infectious diseases that threaten these industries. Using functional genomic approaches, this research investigated the innate immune response in immune tissues (head kidney and spleen) of Atlantic cod following treatment with bacterial antigens (i.e. formalin-killed, atypical Aeromonas salmonicida, referred to as ASAL) or a viral mimic (i.e. polyriboinosinic polyribocytidylic acid, referred to as pIC). This research led to the identification of 4154 expressed sequence tags (ESTs) that were generated from cDNA libraries enriched for transcripts dysregulated following stimulation with ASAL. From these transcripts, 10 genes with immune-relevant functional annotations were selected for quantitative reverse transcription - polymerase chain reaction (QPCR), and the full-length cDNA sequence of Atlantic cod IRF1 was obtained. This study, along with other concurrent studies, collectively identified the biological process of apoptotic regulation as one of the key mechanisms involved in Atlantic cod innate immune responses. Further studies led to the identification and characterization of anti-apoptotic Bcl-2 sub-family genes in Atlantic cod including orthologues of: NR-13, Mcl-1, and Bcl-X. For NR-13, Mcl-1, and Bcl-Xl, the full-length cDNA, genomic sequence, and promoter regions were obtained and thoroughly analyzed. Although only partial cDNA and genomic sequences were obtained for Bcl-X2, the presence of two Bcl-X-like genes in Atlantic cod was evident. In addition, the constitutive gene expression across tissues, and following treatments with ASAL and pIC, were also studied for these 4 genes.

Actions (login required)

View Item