A synthetic oligonucleotide probe (5'TTCCA 3')n uncovers a male specific hybridization pattern in the human genome

A pentanucleotide motif 5'TTCCA3', originating from a 3.4 kb repeat fraction (DYZ1)1, is organized tandemly in the human genome. This motif is abundantly present on the long arm of the human Y (band Yq12) chromosome and is separated by Hae III digestion of male genomic DNA. We have developed a 20 base synthetic oligonucleotide probe, termed OAT20Y, comprising four repeat units of 5'TTCCA3', that uncovers a male-specific hybridization pattern in the human genome. The probe is highly sensitive, since less that 1 micrograms of DNA was sufficient to obtain visible signals after hybridization. Our results on discrimination of sex by using OAT20Y with several amniotic fluid samples was in accordance with clinical data. OAT20Y was found to be specific to the human genome as it did not hybridize with DNA of any non-human species. In addition to sexing human embryos in conjunction with severe X-linked genetic diseases, the probe may be useful in ascertaining the origin of tissues or blood samples in forensic cases.