Identification and structural characterization of two peroxisome proliferator activated receptors and their transcriptional changes at different developmental stages and after feeding with different fatty acids

摘要

Peroxisome proliferator activated receptors betal (PPAR beta 1) and beta2 (PPAR beta 2) were investigated in loath (Misgurnus anguillicaudatus). The PPAR beta 1 and PPAR beta 2 were widely distributed in loath tissues. Multiple alignments of deduced amino acid sequences revealed homologous characteristics of the two subtypes of PPAR beta with 88% identity. PPAR beta 1 was markedly expressed in the liver, about 100-fold higher than liver PPAR beta 2. The two subtypes in unfertilized ovum (UO) showed the highest transcriptions in early life stages, and there were great divergences in expression between unfertilized and fertilized stages. The regulation of PPAR beta 1 and PPAR beta 2 in response to dietary fatty acids was studied in liver of loath fed with diets containing fish oil (FO, rich in n-3 highly unsaturated fatty acid) or soybean oil (SO, rich in 18:2n-6) for 75 days. Results showed that hepatic transcription of PPAR beta 1 in the SO group was higher than in the FO group. However, PPAR beta 2 expression was similar. The differences of molecular characterization, tissue expressions in early life stages, and transcriptional regulation by lipid resources indicated that PPAR beta 1 and PPAR beta 2 were functionally different. This is the first report of differential expression of PPAR beta 1 and PPAR beta 2 in various tissues and early life stages of loath are regulated by lipid resources. These results will stimulate further studies to better understand the functional characterization of PPAR beta 1 and PPAR beta 2. (C) 2015 Elsevier Inc. All rights reserved.