Early immune gene development and expression in African catfish Clarias gariepinus after challenged with Aeromonas hydrophila

Understanding the development of immunity in the early life of fish may help improve the effective management of diseases in aquaculture. However, little is known about the timing of the appearance of different immune-related genes in African catfish C. gariepinus , an important aquaculture species in Africa and Southeast Asia countries. The current study examined the transcriptional onset of immune-related mRNA expression during the development of C. gariepinus and analyzed their expression after pathogenic Aeromonas hydrophila infection. The results showed that the important innate and adaptive immune components mRNA transcripts were detected since the unfertilized eggs of C. gariepinus . The initial development of immune-competence in African catfish was predicted during 30–60 dah. Immune and stress genes were widely expressed in all tissues but mainly in the lymphoid organs and the liver. After the A. hydrophila challenge, the immune genes were modulated rapidly in the liver, spleen, and head kidney. The obtained findings are giving important information in understanding the immune maturation, and for the development of disease management in the African catfish culture.