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Genomic distribution of 5‘ TTCCA 3’ repeat motif and its diagnostic potential in human Y‐chromosome‐related anomalies
Author(s) -
Bala Shasht,
Ahmad Jamal,
Ali Sher
Publication year - 1996
Publication title -
clinical genetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.543
H-Index - 102
eISSN - 1399-0004
pISSN - 0009-9163
DOI - 10.1111/j.1399-0004.1996.tb02388.x
Subject(s) - biology , autosome , human genome , x chromosome , genetics , chromosome 22 , microbiology and biotechnology , restriction fragment length polymorphism , restriction enzyme , genomic dna , chromosome , chromosome 21 , hybridization probe , gonadoblastoma , y chromosome , population , genome , dna , karyotype , gene , polymerase chain reaction , demography , sociology
We have studied genomic distribution of a simple repeat motif 5′ TTCCA 3′ derived from the DYZ1 fraction of the human Y chromosome employing restriction fragment length polymorphism and in situ hybridization techniques. This has led us to develop a synthetic DNA based genetic marker specific to human genome. Randomly selected human genomic DNA from both sexes, digested with a total of 16 restriction enzymes, hybridized with OAT20Y probe comprising four repeat units of 5′ TTCCA 3′ motif failed to reveal fragment length polymorphisms. In contrast, with most of the enzymes, several multilocus monomorphic bands and with a few enzymes, smeary signals were detected. In situ hybridization of the OAT20Y probe with human chromosomes revealed grains on the long arm of the Y chromosome, whereas the X‐chromosome and autosomes showed random distribution of the grains without any preferential labeling in the centromeric or telomeric regions. The OAT20Y probe uncovers a 3.4 kb isomorphic band exclusively in the human male DNA digested with Hae III enzyme. Using the OAT20Y probe, we have detected the presence of Y chromosome in mosaic cell populations of Turner's patients with dysgenetic gonads and high levels of LS/FSH. The presence of Y chromosome in these patients has been associated with an increased risk of gonadoblastoma. The OAT20Y probe offers sensitivity and accuracy for the detection of Y‐chromosome‐bearing cells in a mosaic cell population and, consequently, help in better management of the patients.