Clone pJA36B (DYS14) was isolated from a human Y chromosome enriched cosmid library. Southern blot analysis revealed a male-specific hybridization pattern. Deletion mapping with patients' DNA localized pJA36B to the median region of Yp, being present in the DNA of nine of fifteen XX-males tested so far and therefore localized in the region neighbouring the TDF-locus. Northern blot analysis showed a transcription signal in poly(A)+ RNA of human testis. Sequence analysis of the genomic DNA sequence revealed an open reading frame of 522 basepairs in the absence of control or signal sequences for the regulation of transcription or polyadenylation. This suggests that only one exon of a translatable sequence is present in clone pJA36B. A computer aided search revealed no significant homologies with known DNA or protein sequences.