RESUMEN
The aim of this study was to investigate the expression of MHCⅠ gene in different tissues of Rana dybowskii under the stress of Aeromonas hydrophila (Ah), and to provide evidence for revealing the anti-infective immune response mechanism of amphibians. The experimental animal model of Aeromonas hydrophila infection was first constructed, and the pathological changes were observed by HE staining. The MHCⅠ gene α1+α2 peptide binding region of Rana dybowskii was cloned by RT-PCR and analyzed by bioinformatics. Real-time PCR was used to detect the transcription level of MHCⅠ in different tissues under Ah stress. After Ah infection, the skin, liver and muscle tissues showed signs of cell structure disappearance and texture disorder. The MHCⅠ gene α1+α2 peptide binding region fragment was 494 bp, encoding 164 amino acids, and homology with amphibians. Above 77%, the homology with mammals was as low as 14.96%, indicating that the α1+α2 region of MHC gene was less conserved among different species. The results of real-time PCR show that the liver, spleen and kidney of the experimental group were under Ah stress. The transcript levels of MHCⅠ gene in skin and muscle tissues were higher than those in the control group at 72 h, but the time to peak of each tissue was different (P<0.01), indicating that the response time of MHCⅠ gene in different tissues was different under Ah stress. This study provides a reference for further exploring the immune function of MHC molecules in anti-infection.