Abstract
Nuclear factor-E2-related factor (Nrf) belongs to the Cap ‘n’ collar basic leucine zipper (CNC-bZIP) family, which plays an important role in the resistance to oxidative stress in the body. In this study, 12 Nrf genes were identified in the common carp genome database. Comparative genomic analysis showed that the Nrf genes of common carp had significant amplification, confirming that the common carp had experienced four genome-wide replication events. Phylogenetic analysis showed that all common carp Nrf clustered with scleractinian fish Nrf, indicating that they were highly conserved during evolution. In addition, tissue distribution results showed that most Nrf genes had a broad tissue distribution but exhibited tissue-specific expression patterns, demonstrating functional differences after WGD events. At 30 and 60 days of Cd2+ stress, most of the Nrf genes showed an increase in expression compared with the control group, indicating that they played a key role in the organism’s response to oxidative stress. To find a suitable concentration of Bacillus coagulans to activate the Nrf genes, we added three different concentrations (2.0 × 107 CFU/g, 2.0 × 108 CFU/g, and 2.0 × 109 CFU/g) of B. coagulans into the feed and defined them as L1, L2, and L3 groups, respectively. We investigated the effect of different concentrations of B. coagulans in the feed on the expression level of Nrf genes in the intestine of common carp under Cd2+ stress at 30 and 60 days. The results showed that, compared with the control/stress group, the expression of different Nrf genes was improved to varying degrees at three concentrations, and the effect of the L2 group (2.0 × 108 CFU/g) was the best. This suggests that the L2 group is the optimum concentration for activating Nrf gene expression when subjected to heavy metal Cd2+ stress and may act as an activation switch with a prominent role in the body’s resistance to oxidative stress and immune response.
Highlights
Nuclear factor-E2-related factor (Nrf ) belongs to the Cap ‘n’ collar basic leucine zipper (CNC-bZIP) family; it is an important class of regulatory factors that can be involved in oxidative stress response and detoxification of the body [1]
A total of 12 Nrf genes were identified in the common carp genome database, distributed on 11 chromosomes (Table 2), significantly more than the number of Nrf genes in other vertebrates
This study presented the first identification of the Nrf gene family in common carp
Summary
Nuclear factor-E2-related factor (Nrf ) belongs to the Cap ‘n’ collar basic leucine zipper (CNC-bZIP) family; it is an important class of regulatory factors that can be involved in oxidative stress response and detoxification of the body [1]. Nrf was a gene identified in a cDNA library screen as binding to the erythrocyte-specific NF-E2/AP1 consensus sequence found in the 5 β-globin locus control region 5 -GCTGAGTCA-3 , widely expressed in various tissues of animals. It participates in many cellular activities such as redox reactions, mitochondrial respiration, inflammatory responses, lipid metabolism, and cell differentiation [5,6]. As a repressor of gene expression, Nrf plays a vital role in the antioxidant stress response to glutathione homeostasis
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
