Objective To determine the activity of TBX1 gene promoter, and identify the critical region of TBX1 gene promoter. Methods TBX1 gene promoters with
different length were isolated and amplified by PCR, digested and inserted into pGL3-Basic reporter gene vector. 293T and COS7 cells were transiently
transfected with reporter plasmids containing TBX1 gene promoters with different length using FuGene HD. Forty-two hours later, the activity of TBX1 gene
promoters with different length was compared with luciferase detection. Results There were differences in activity among TBX1 gene promoters with different
length, and the activity of TBX1 gene promoters with 5 kb and 1.2 kb in length was higher. The activity of TBX1 gene promoters varied in different cells,
with the highest activity of TBX1 gene promoter with 5 kb in length in COS7 cells and that with 1.2 kb in length in 297T cells. Conclusion In transcriptional
level, TBX1 promoter could activate the expression of reporter gene. The activity varies among promoters with different length. It is suspected that 1.2 kb
upstream region of transcript start site is critical to TBX1 gene promoter.