Location: Cool and Cold Water Aquaculture ResearchTitle: Production of homozygous transgenic rainbow trout with enhanced disease resistance Author
Submitted to: Marine Biotechnology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/16/2013
Publication Date: 6/1/2014
Citation: Chiou, P.P., Chen, M.J., Lin, C., Khoo, J., Larson, J., Holt, R., Leong, J., Thorgarrd, G., Chen, T.T. 2014. Production of homozygous transgenic rainbow trout with enhanced disease resistance. Marine Biotechnology. 16(3): 299-308. DOI 10.1007/s10126-013-9550-z. Interpretive Summary: We report the production of disease resistant rainbow trout created by introducing an antimicrobial peptide gene into the genome using gene transfer technology. Eight families were established that exhibited resistant characteristics to infection by Aeromonas salmonicida and infectious hematopoietic necrosis virus (IHNV). These fish can be used to identify genes affecting disease resistant characteristics. In addition, the technique established in this paper can be applied to increase disease resistance in any aquaculture species.
Technical Abstract: Previous studies conducted in our laboratory showed that transgenic medaka expressing cecropin B transgenes exhibited resistant characteristic to fish bacterial pathogens, Pseudomonas fluorescens and Vibrio anguillarum. To confirm whether antimicrobial peptide gene will also exhibit antibacterial and anti-viral characteristics in aquaculture important fish species, we produced transgenic rainbow trout expressing cecropin P1 or a synthetic cecropin B analog, CF-17, transgene by sperm-mediated gene transfer method. About 30 % of fish recovered from electroporation were shown to carry the transgene as determined by polymerase chain reaction (PCR) amplification assay. Positive P1 transgenic fish were crossed to nontransgenic fish to establish F1 transgenic founder families, and subsequently generating F2, and F3 progeny. Expression of cecropin P1 and CF-17 transgenes was detected in transgenic fish by reverse transcription (RT)-PCR analysis. The distribution of body sizes among F1 transgenic fish were not significantly different from those of non-transgenic fish. Results of challenge studies revealed that many families of F2 and F3 transgenic fish exhibited resistance to infection by Aeromonas salmonicida and infectious hematopoietic necrosis virus (IHNV). All-male homozygous cecropin P1 transgenic families were produced by androgenesis from sperm of F3 heterozygous transgenic fish in one generation. The resistant characteristic to A. salmonicida was confirmed in progeny derived from the outcross of all-male fish to non-transgenic females. Results of our current studies confirmed the possibility of producing disease-resistant homozygous rainbow trout strains by transgenesis of cecropin P1 or CF-17 gene and followed by androgenesis.