RESUMEN
Muscle accretion is affected by the difference between protein synthesis and its degradation. Studies on different species revealed that muscle proteolysis is mediated by different pathways including the ubiquitin-proteasome pathway in which the ubiquitin protein ligases play an important role. These muscle atrophy associated ligases were not well studied in tilapia. In this study, we characterized the ubiquitin protein ligases MuRF1/2/3, Atrogin-1 and F-box25, members of the ubiquitin-proteasome pathway in tilapia, Oreochromis niloticus, and their expressions in the muscle of starved, fed, refed, and control fish. Sequences of these genes revealed presence of Ring finger, B-box, and Cos domains in all MuRF genes, as well as F-box domain in Atrogin-1 and F-box25 genes. Real-time qPCR data analysis showed that expression of MuRF1/2/3, Atrogin-1, F-box25, and proteasome complex genes was significantly upregulated in starved fish compared to fed fish. Concurrently, the proteasome activity was 1.7-folds elevated in the starved fish compared to fed fish. These results confirm the important role of these genes in muscle degradation and suggest potential usage as markers of muscle accretion in tilapia.
Asunto(s)
Cíclidos/genética , Proteínas de Peces/genética , Proteínas Musculares/genética , Inanición/genética , Proteínas de Motivos Tripartitos/genética , Ubiquitina-Proteína Ligasas/genética , Alimentación Animal , Animales , Cíclidos/metabolismo , Proteínas F-Box/genética , Expresión Génica , Complejo de la Endopetidasa Proteasomal/genética , Complejo de la Endopetidasa Proteasomal/metabolismoRESUMEN
In this study, the effects of fish diet contaminated with Cu, Cd and Cu+Cd on Nile tilapia, was demonstrated by evaluating its bioaccumulation in the muscle and by testing the cytogenetic profile. Fish exposed to diet contaminated with Cu, Cd or their mixture had a significant increase in the number of chromosomal abnormalities and an inhibition of the mitotic index. Our study revealed high muscle Cu or Cd content in fish fed with diet contaminated with high dietborne Cu, Cd, Cu and Cd. It also revealed that the chromosomal abnormalities were higher for fish fed diet Cd contaminated and Cu+Cd contaminated diets than those fed diet Cu contaminated diet. Thus, maybe fish diets contaminated with Cu, Cd, Cu+Cd induced genotoxicity and mutation. Also, maybe high concentrations of Cu and Cd in fish tissue resulted from feeding on Cu and Cd contaminated diets, are dangerous for human consumption.