A comparative study of immune response between hybrid yellow catfish Huangyou-1 and its parental populations after challenge with Aeromonas hydrophila or Edwardsiella ictaluri

Bacterial septicemia and red-head disease are crucial factors restricting the development of yellow catfish. The hybrid yellow catfish Huangyou-1 from female Pelteobagrus fulvidraco and male Pelteobagrus vachelli, has been a successful crossbreed, while the hybrids show advantages in growth performance. In the present study, we analyzed the survival rates, the expressions of copper-zinc superoxide dismutase (Cu/ZnSOD), manganese superoxide dismutase (MnSOD), and lysozyme (Lyz) as well as SOD and Lyz activity after challenge with Aeromonas hydrophila or Edwardsiella ictaluri between the hybrid and its parental species. Results showed that hybrid population possessed higher survival rate than its parental populations after pathogen challenge. The fold change of Cu/ZnSOD and MnSOD at the mRNA and protein level as well as SOD activity in hybrid were higher than those of both parental populations after pathogen challenge. Hybrid population showed the highest fold change of Lyz at the mRNA and enzyme activity after challenge with A. hydrophila or E. ictaluri. Moreover, the increased SOD and Lyz activity in hybrid indicated the response or the recognition capacity was increased. Our study suggested hybrid may be more active in non-specific immune response after pathogen infection and potential breeding prospects compared with its parental populations. Our findings provided valuable insights into the heterosis in the novel hybrid yellow catfish Huangyou-1, which could help us better understand heterosis in yellow catfish aquaculture.