Molecular Characterization and Gene Expression of Glutathione Peroxidase 1 in Tor tambroides Exposed to Temperature Stress

Abstract

Temperature is an abiotic factor that affects various biological and physiological processes in fish. Temperature stress is known to increase the production of reactive oxygen species (ROS) that subsequently cause oxidative stress. Fish is known to evolve a system of antioxidant enzymes to reduce ROS toxicology. Glutathione peroxidase (GPx) family consists of key enzymes that protect fish from oxidative stress. In this study, full-length GPx1 cDNA (GenBank accession no. KY984468) of Tor tambroides was cloned and characterized by rapid amplification of cDNA ends (RACE). The 899-base-pair (bp) GPx1 cDNA includes a 576-bp open reading frame encoding for 191 amino acids, plus 28 bp of 5′-untranslated region (UTR) and 295 bp of 3′-UTR. Homology analysis revealed that GPx1 of T tambroides (Tor-GPx1) shared high similarity with GPx1 sequences of other fish species. The phylogenetic construction based on the amino acid sequence showed that Tor-GPx1 formed a clade with GPx1 sequences of various fish species. Real-time polymerase chain reaction (PCR) was performed to assess the levels of GPx1 gene expression in the liver and muscle of T tambroides under thermal stress. The results indicated that GPx1 gene expression was down-regulated under decreased temperature. However, there was no significant difference between GPx1 gene expression in fish exposed to high temperature and control. Our study provides the first data regarding GPx gene expression in T tambroides under thermal stress.

Comparison of Circulating Markers and Mucosal Immune Parameters from Skin and Distal Intestine of Atlantic Salmon in Two Models of Acute Stress

“…However, fish are known to have developed an antioxidant enzyme system to reduce ROS. Among these enzymes, GPx is a key protein that protects fish from oxidative stress [26]. Our data support this idea, as we detected significantly increased levels of GPx activity at 12 h post-hypoxia stress.…”

Antioxidant Activities and Selenogene Transcription in the European Sea Bass (Dicentrarchus labrax) Liver Depend, in a Non-linear Manner, on the Se/Hg Molar Ratio of the Feeds

“…In that regard, it is interesting to note that also the gene regulation response registered by our work seems to be dependent on the Se/ Hg molar ratio of the feed and not on the Hg concentration alone. However, it must also be borne in mind that the response may be different depending on the stressor: cold temperature stress, for example, induced a downregulation of gpx1 redox genes in the cyprinid Tor tambroides [36], but infection with a pathogen induced the expression at the transcriptional level of both txn and txnrd in rainbow trout [15]. The upregulation in the transcription of the genes txn1, gpx1, and txnrd2 observed in A2 relative to A1 parallels a higher DNTB-reductase activity in these groups, while the increase in TrxR activity in A2 mirrors the upregulation of txn1 and txnrd2.…”

Summer Mortality Syndrome Affecting Cultured European Seabass at Kafrelsheikh Province, Egypt

“…The present results showed that water temperature above 30 • C induces oxidative stress in D. labrax accompanied by ROS production. This finding is supported by the research conducted by Kamyab et al (2017) and Do et al (2019). Biller and Takahashi (2018) reported that oxidative stress limits the immune response by impairing the defense mechanism associated with ROS production to decrease ROS production.…”