The cloning of size-heterogeneous, Y-specific repetitive DNAs and their clinical application

Four Y-specific DNAs of different sizes were isolated by screening a human Y-chromosome gene-library. After determining their structural characteristics, the possibility for their clinical application was examined. The results are as follows: 1. The 4 cloned DNAs had inserts of 3.3, 2.0, 1.9 and 1.4 kb; they were subcloned into plasmid pUC19, and designated pKY-2, pKY-3, pKY-4 and pKY-5, respectively. 2. All four clones hybridized specifically with the Y-specific 3.5 kb DNA but not with female DNA. However, they did not cross-hybridize with the 2.1 kb fragment known to be another Y-specific repetitive DNA of human genomes. 3. The newly cloned probes were applied to the detection of Y-specific DNA in abnormal Y-chromosomes [Turner Syndrome (45, X/46, X, -X, + marker), 46, XY-female, mosaicism (46, XY/47, XYY), 46, XX-male and super male (47, XYY)]. 4. Since the newly cloned DNAs did not hybridize with other eukaryotic genome DNAs such as monkey, rat, mouse, chicken, frog, or fish, their human gene specificities were confirmed.