USDA NIFA funded research leads to new knowledge in catfish breeding in low oxygen environments

Project director, Dr. Zhangjiang (John) Liu, Associate Provost/Associate VP-Research & Professor in the School of Fisheries, Aquaculture and Aquatic Sciences along with his research team comprised of Auburn Faculty members Rex Dunham and Eric Peatman and UAB Faculty member Degui Zhi, completed a study in August 2016 on Enhancing low-oxygen tolerance of catfish using genomics and genetics.  The two year research project funded by the USDA NIFA Special Research Grants in Aquaculture Research Program produced exciting results as the project summary below reveals.

Catfish is the leading aquaculture species for US aquaculture. In recent years, however, it has encountered unprecedented challenges due to fierce international competition and various production problems. Among these, the catfish industry lose tens of millions of fish due to mortalities caused by hypoxia alone, and more importantly, hypoxic exposures cause slow growth and induce disease outbreaks that in turn cause losses of hundreds of million dollars annually.  Among many things, it is widely believed that genetics research will provide the permanent solutions to the problems. In particular, application of modern genomics technologies will allow rapid and precise selection of superior brood stocks.  Our long-term goal is to enhance catfish stocks with superior performance traits to support a sustainable and profitable aquaculture industry. To reach this long-term goal, in this project, we will identify closely linked markers to the major gene locus controlling low-oxygen tolerance, and validate and apply such markers for selection of channel catfish and blue catfish used for the production of hybrid catfish, providing immediate benefits to the catfish industry. A major discovery of this project was the complexity of the genetic architecture of tolerance to low dissolved oxygen. In the early stages of this work, use of only one family led us to believe that a single locus could have been responsible for tolerance to hypoxia. However, additional studies reveal the complex nature of genetics for low oxygen tolerance. This discovery changed the community thinking on how to address the low oxygen tolerance through breeding.

Publications (Click to read publications associated with this project)

1. Wang X, Liu S, Jiang C, Geng X, Zhou T, Li N, Bao L, Li Y, Yao J, Yang Y, Jin Y, Dunham R, Liu ZJ. 2017. Multiple across-strain and within-strain QTLs suggest highly complex genetic architecture for hypoxia tolerance in channel catfish. Molecular Genetics and Genomics 292: 63–76. DOI:10.1007/s00438-016-1256-2

2. Wang X, Liu S, Dunham R, Liu ZJ. 2017. Effects of strain and body weight on low-oxygen tolerance of channel catfish. Aquaculture International, in press.

3. Zhong X, Wang X, Zhou T, Jin Y, Tan S, Jiang C, Geng X, Li N, Shi H, Zeng Q, Yang Y, Yuan Z, Bao L, Tian C, Liu S, Li Q, Liu ZJ. 2017. Genome-wide association study reveals multiple novel QTL associated with low-oxygen tolerance in hybrid catfish. Marine Biotechnology, in press.

4. Jin Y, Zhou T, Liu S, Geng X, Chen A, Yao J, Jiang C, Wang X, Su B, Liu ZJ. 2016. A genome-wide association study (GWAS) of heat stress-associated SNPs in catfish. Animal Genetics, doi: 10.1111/age.12482.

5. Fu Q, Zeng Q, Li Y, Yang Y, Li C, Zhou T, Li N, Liu S, Yao J, Jiang C, Li D, Liu ZJ. 2017. The chemokinome superfamily in channel catfish: I. CXC subfamily and their involvement in disease defense and hypoxia responses. Fish and Shellfish Immunology 60: 380-390.

6. Yuan Z, Liu S, Yao J, Zeng Q, Liu ZJ. 2016.  Expression of Bcl-2 genes in channel catfish after bacterial infection and hypoxia stress. Developmental and Comparative Immunology 65: 79-90.

7. Tian Y, Yao J, Liu S, Jiang C, Zhang J, Li Y, Liu ZJ. 2015. Identification and expression analysis of 26 oncogenes of the receptor tyrosine kinase family in channel catfish after bacterial infection and hypoxic stress. Comparative Biochemistry and Physiology Part D, Genomics and Proteomics 14:16-25.

8. Sun L, Liu S, Bao L, Li Y, Feng J, Liu ZJ. 2015. Claudin multigene family in channel catfish and their expression profiles in response to bacterial infection and hypoxia as revealed by meta-analysis of RNA-Seq datasets. Comparative Biochemistry and Physiology, Part D, Genomics and Proteomics 13:60-69.

For further information on Dr. Liu’s research, please visit his website.