Skip to main content
ARS Home » Southeast Area » Auburn, Alabama » Aquatic Animal Health Research » Research » Publications at this Location » Publication #410220
Research Project: Integrated Research to Improve Aquatic Animal Health in Warmwater Aquaculture

Location: Aquatic Animal Health Research

Title: Time-course gene expression analysis of the early immune response of Nile tilapia bred for resistance to Streptococcus iniae reveals candidate genes underlying major QTL

Author
item Abernathy, Jason
item Lafrentz, Benjamin
item Shoemaker, Craig
item PEATMAN, ERIC - Auburn University
item Lange, Miles
item VELA-AVITUA, SERGIO - Benchmark Genetics
item LOZANA, CARLOS - Benchmark Genetics
item OSPINA-ARANGO, JOSE - Spring Genetics
item Beck, Benjamin
item RYE, MORTEN - Benchmark Genetics

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 12/20/2023
Publication Date: 1/12/2024
Citation: Abernathy, J.W., Lafrentz, B.R., Shoemaker, C.A., Peatman, E., Lange, M.D., Vela-Avitua, S., Lozana, C.A., Ospina-Arango, J.F., Beck, B.H., Rye, M. 2024. Time-course gene expression analysis of the early immune response of Nile tilapia bred for resistance to Streptococcus iniae reveals candidate genes underlying major QTL [ABSTRACT]. 31st International Plant and Animal Genome Conference, San Diego, CA. Jan 11-17, 2024.

Interpretive Summary:

Technical Abstract: Due to its high adaptability, Nile tilapia (Oreochromis niloticus) is among the most important cultured aquatic species worldwide. Tilapia farming has grown at a faster rate than overall aquaculture in the past two decades, leading to more intensive production but also to an increase in occurrence of diseases. Streptococcal disease, caused by Streptococcus iniae, S. agalactiae and S. dysgalactiae, is a major bacterial disease affecting tilapia populations worldwide. Due high morbidity and mortality rates, this disease causes a substantial negative economic impact to the global tilapia industry. Previously, Genome Wide Association Study (GWAS) was performed on Nile tilapia that have been selected for resistance to Streptococcus iniae and a major Quantitative Trait Loci (QTL) was identified on linkage group (LG) 8. Initially, 62 genes were identified as candidate loci given position of significant single nucleotide polymorphisms (SNPs). Here, we sequenced mRNA libraries from liver (n=48) and spleen (n-48) from both S. iniae resistant and susceptible lines of Nile tilapia at 2 h, 4 h, 8 h, 12 h, and 24 h post infection and characterized global gene expression compared to uninfected controls. We identified thousands of differentially expressed genes (DEGs) between lines, with major ontologies related to iron binding and homeostasis, defense response to bacteria, proteosome and peroxisome-activating activity, lipid and fatty acid metabolism, regulation of apoptotic processes, and innate immune response in liver. In spleen, immune system processes, immune response and production of molecular mediators of immune response, defense response, B-cell and lymphocyte-mediated immunity, phagocytosis, and inflammatory response gene ontologies were significantly perturbed between groups. Then, using time-course gene expression analyses with weighted gene co-expression network analysis (WGCNA) provided us the ability to integrate GWAS-derived SNPs with co-expression networks to prioritize our list of candidate genes. Further analysis of our bulk RNA-seq data allowed for the inference of gene regulatory networks and identify hub genes. Significant results from differential gene expression analyses and gene network analyses will be presented and discussed.