T-box transcription factor eomesodermin/Tbr2 in Atlantic cod (Gadus morhua L.): Molecular characterization, promoter structure and function analysis

• Published in: Fish & Shellfish Immunology
• Main Authors: Chi, Heng, Sørmo, Kristian Gillebo, Diao, Jing, Dalmo, Roy Ambli
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier 2019
• Subjects: VDP::Mathematics and natural science: 400::Basic biosciences: 470::Genetics and genomics: 474; VDP::Matematikk og Naturvitenskap: 400::Basale biofag: 470::Genetikk og genomikk: 474; atlantic cod; Gadus morhua
• Online Access: https://hdl.handle.net/10037/17710; https://doi.org/10.1016/j.fsi.2019.07.021

Eomesodermin (Eomes) is a member of T-box transcription factor family and plays an important role in the regulation of a wide variety of developmental processes and immune response in animals. Here we report cloning and characterization of the full-length cDNA of Atlantic cod Eomes (GmEomes), which possesses a TBOX_3 domain similar to its counterpart in mammals. The regulated expression was observed in head kidney and spleen in response to live Vibrio anguillarum infection in vivo , and spleen leukocytes in vitro after PMA and poly I:C stimulation. Furthermore, we determined a 694 bp sequence, upstream of the transcriptional start site (TSS), to contain a number of sequence motifs that matched known transcription factor-binding sites. Activities of the presumptive regulatory gene were assessed by transfecting different 5′-deletion constructs in CHSE-214 cells. The results showed that the basal promoters and positive transcriptional regulator activities of GmEomes were dependent by sequences located from −694 to −376 bp upstream of TSS. Furthermore, we found that some Eomes binding sites were present in the 5′-flanking regions of the cod IFNγ gene predicted by bioinformatics. However, Co-transfection of eomesodermin overexpression plasmids with INFγ reporter vector into CHSE-214 cells determined that Atlantic cod eomesodermin played a minor role in activation of the INFγ promoter.