Location: Cool and Cold Water Aquaculture ResearchTitle: Identification of single nucleotide polymorphism markers associated with bacterial cold water disease resistance and spleen size in rainbow trout
|HERNANDEZ, ALVARO - University Of Illinois|
|Wiens, Gregory - Greg|
Submitted to: Frontiers in Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/9/2015
Publication Date: 9/24/2015
Citation: Liu, S., Vallejo, R.L., Palti, Y., Gao, G., Marancik, D.P., Hernandez, A.G., Wiens, G.D. 2015. Identification of single nucleotide polymorphism markers associated with bacterial cold water disease resistance and spleen size in rainbow trout. Frontiers in Genetics. 6:298. doi:10.3389/fgene.2015.00298.
Interpretive Summary: Understanding disease resistance is essential for improving production efficiency of rainbow trout. Bacterial cold water disease is one of the frequent causes of elevated mortality on rainbow trout farms. Previously, we reported that spleen size can predict resistance to cold water disease in rainbow trout. In this study, we used the latest sequencing technology to identify molecular markers associated with bacterial cold water disease resistance and spleen size. As a result, we identified 18 markers associated with disease resistance and 20 markers associated with spleen size. The markers identified in this study may be useful for selective breeding of rainbow trout for improved disease resistance and for studies aimed to further improve our understanding of molecular mechanisms involved in fish resistance to infectious diseases.
Technical Abstract: Bacterial cold water disease (BCWD) is one of the frequent causes of elevated mortality in salmonid aquaculture. Previously, we identified and validated microsatellites associated with QTL (quantitative trait loci) for BCWD resistance and spleen size in rainbow trout. The objective of this study was to identify single nucleotide polymorphism (SNP) markers associated with BCWD resistance and spleen size using both genome-wide association studies (GWAS) and QTL mapping approaches. A total of 298 offspring from the two half-sib families used in our previous study to validate the significant BCWD QTL on chromosome Omy19 were genotyped with RAD-seq (restriction-site-associated DNA sequencing), and 7,849 informative SNPs were identified. Based on GWAS, 18 SNPs associated with BCWD resistance and 20 SNPs associated with spleen size were identified. QTL mapping revealed three significant QTL for BCWD resistance. In addition to the previously validated dam-derived QTL on chromosome Omy19, two significant BCWD QTL derived from the sires were identified on chromosomes Omy8 and Omy25, respectively. A sire-derived significant QTL for spleen size on chromosome Omy2 was detected. Consistent with our previous study, there was no spleen size QTL derived from the dam on chromosome Omy19 in mapping family 2012474. The SNP markers reported in this study will facilitate fine mapping to identify positional candidate genes for BCWD resistance in rainbow trout.