Background: The erythroid transcription factor GATA‐1 is also expressed in Sertoli cells of the testis. The testicular expression of GATA‐1 is regulated in a developmental and spermatogenic stage‐specific manner. To further clarify the regulatory mechanisms of testicular GATA‐1 gene expression, we carried out transgenic reporter gene expression analyses.

Results: We found that GATA‐1 expression in Sertoli cells is markedly decreased concomitant with the emergence of elongated spermatids in the seminiferous tubules. Transgenic reporter mouse analyses revealed that a 15 kb GATA‐1 genomic region is sufficient to recapitulate the gene expression profile in Sertoli cells. While the GATA‐1 haematopoietic enhancer and the proximal first exon are included within the 15 kb genomic region, these regulatory elements are not essential for GATA‐1 expression in Sertoli cells. Further analyses using deletion constructs revealed that a 1.5 kb region 5′ to the GATA‐1 haematopoietic enhancer is essential for gene expression in Sertoli cells and this region is referred to as the GATA‐1 testis activation region.

Conclusion: These results thus demonstrated that the GATA‐1 testis activation region is essential for Sertoli cell‐specific expression of GATA‐1 gene. The 15 kb genomic region is applicable and useful for the expression vector system specific for adult Sertoli cells in stage VII to IX.