We have cloned and sequenced transcripts from the X- and Y-linked zinc-finger genes ZFX and ZFY respectively and discuss a possible mechanism of post-transcriptional control by which these genes can be widely expressed but translated in only specific tissues. We report the identification of a novel 3'UTR (untranslated region) present in ZFY which is highly conserved among primates and contains a series of motifs implicated as mRNA instability determinants. These sequences can be substantially removed by polyadenylation directed from consensus (AATAAA) and non-consensus (AATATAAA) sequences in adult testis. The DNA-binding domains of the ZFY and ZFX proteins are compared using present models for zinc-finger/DNA interactions. Additionally, the genomic organisation of the ZFY coding sequence is presented as compared to that of ZFX.