| Apostichopus japonicus is one of the most economic output aquaculture species in China.When sea water temperature rises to some level in summer,A.japonicus will enter into aestivation.Aestivation undoubtedly shortens the growing cycle of A.japonicus and brings economic losses,Which is a hot spot in the study of A.japonicus.FoxO(Forkhead box O)as a transcriptional regulator factor,plays an important role in the regulation of reactive oxygen species(ROS)levels,proliferation and differentiation of cell,regulation of transcriptional,regulation of stress,regulation of immune,and signal transduction pathways.Nrf1(NF-E2-related factor 1)as a transcription factor that is activated by Keap1(kelch-like ECH-associated protein-1)in response to oxidative stress and binds the antioxidant response element ARE,which regulates a series of antioxidant genes and participates in oxidative stress.Peroxireoxin(Prx)is an important component of the antioxidant system of organisms.Therefore,important defense regulatory genes of FoxO,Keap1,Nrf1 and Prxs play an important role in antioxidant defense system.In this study,the selected antioxidant defense regulatory genes were compared with the amino acid sequences of multiple species to carry out multiple sequence alignment and homology analysis,and the biological information was analyzed.In order to study the effects of aestivation on antioxidant function and expression of Keap1/Nrf1 and FoxO related genes in various tissues of A.japonicus,The A.japonicus was raised at 15±0.5°C for 7 days and then heated at 1°C/d until the desired temperature was reached.then keep 25±0.5°C 10 days and then cooled down to 15°C at 1°C/d.At the four time of 7 d,18 d,28 d and 40 d,tissue samples of 4 heads of A.japonicus which were randomly selected for detection.The expression of FoxO,Keap1-Nrf1 pathway and its downstream Prxs genes in different periods of aestivation were detected.The body wall,muscle,intestinal,respiratory tree and coelomocytes tissue samples of A.japonicus were used to detect the expression of FoxO,Keap1-Nrf1 pathway and its downstream Prxs.In thermal induced aestivated sea cucumbers,the expression of FoxO got increase in muscle and respiratory tree and the expression of Keap1 and Nrf1 got increase in intestinal and respiratory tree,and the expression of its downstream gene PRDX2、PRDX3、PRDX4、PRDX5increased significantly.These results indicat that the aestivation has led to the oxidative stress of A.japonicus,and FoxO and Keap1/Nrf1 pathways may play an important role in anti-oxidative stress.To investigate SNPs in FoxO and Nrf1 genes and the correlation between the SNPs and antioxidant capacity of A.japonicus.Direct sequencing method of PCR products was used to detect Polymorphism of FoxO and Nrf1 Gene Promoters with 30high antioxidant capacity individuals and 30 low antioxidant capacity individuals.The results indicate that One SNP site-310 A-C was detected in FoxO,and-113 T-C and-116 G-A 2 sites were detected in Nrf1 with polymorphism.The allele frequency distribution was in accordance with Hardy Weinberg’s equilibrium law(P>0.05).The allele frequencies were calculated and the correlation between the polymorphism of the loci and antioxidant traits was examined by Chi-square(χ~2).These results suggested that the three SNPs were correlated with the trait of antioxidant capacity of A.japonicus. |
