The recently discovered ADAMTS16 gene (a disintegrin and metalloproteinase domain with thrombospondin motifs) encodes a metalloproteinase with yet unknown physiological function. Based on structural similarity with other ADAMTS members one would predict a role for ADAMTS16 in extracellular matrix degradation and in the control of angiogenesis. Most recent observations suggest a link between ADAMTS16 gene polymorphisms and arterial hypertension. The objective of this study was to investigate the expression pattern of ADAMTS16 and to identify transcriptional pathways involved in its regulation. In situ mRNA hybridization (ISH) and immunohistochemistry revealed abundant ADAMTS16 mRNA and protein in the developing kidneys and gonads. Strikingly, ADAMTS16 was co-expressed with the Wilms' tumor transcription factor, WT1, which is necessary for normal formation of the kidneys and gonads, in Sertoli cells of the testis and in granulosa cells of the ovary. Knockdown of WT1 in mesonephros-derived M15 cells by RNA interference reduced ADAMTS16 mRNA by 90±3% (n=5) compared to transfection with non-targeting siRNA. Conversely, forced expression of WT1 increased ADAMTS16 transcripts more than 5-fold in human embryonic kidney (HEK) 293 cells. In silico analysis with the Transfac® software detected 11 potential WT1 binding elements in the promoter of the ADAMTS16 gene in proximity to the transcription start site. A reporter construct containing the luciferase gene under control of the ADAMTS16 promoter was activated more than 3-fold by transient co-transfection of a WT1 expression construct. In conclusion, these findings suggest a role for ADAMTS16 in the formation of the kidneys and gonads. It is proposed that the ADAMTS16 metalloproteinase is involved in tissue remodelling in the testis and ovary. Furthermore, our results identified the product of the Wilms' tumor gene WT1 as a potential transcriptional regulator of ADAMTS16.