Molecular Cloning and Preliminary Characterization of the Thioredoxin Reductase Gene (TXNRD۱) in Ovis aries

Thioredoxin reductase (TrxR/TXNRD۱) is a selenoenzyme that occupies a central position in cellular redox homeostasis and modulates diverse processes, including disulfide reduction, redox-dependent regulation of transcription factors, DNA synthesis, apoptosis, and immune responses. Overexpression or dysregulation of TXNRD۱ has been implicated in cancer progression and is being explored both as a prognostic biomarker and a therapeutic target. Despite extensive characterization in several mammalian models, the ovine (sheep) TXNRD۱ sequence and gene structure remain incompletely characterized, limiting species-specific functional studies and comparative analyses. In this study, we report the molecular cloning of a ۳۷۹-base-pair (bp) partial fragment of the ovine thioredoxin reductase transcript amplified from thyroid (and liver) cDNA. The fragment was amplified by nested RT–PCR, subcloned into the pGATA vector, and confirmed by restriction analysis, spectrophotometry, and Sanger sequencing. This partial sequence provides a validated template for rapid amplification of cDNA ends (۳′/۵′ RACE) to obtain the full-length ovine TXNRD۱ transcript and open reading frame; obtaining the complete sequence will enable domain mapping, comparative phylogenetic analysis and functional assays (e.g., expression of recombinant protein and assessment of redox activity). Established RACE methodologies and recent improvements for accurate ۵′/۳′ end mapping are well-suited to extend this work. Overall, the cloned fragment represents a first experimental step toward defining ovine TXNRD۱ and lays the groundwork for downstream studies into its physiological roles and potential clinical relevance in sheep.

کلیدواژه ها:

Thioredoxin reductase ، Ovis aries ، Molecular cloning ، Redox regulation ، Selenoenzyme