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Identification of human G–group and Y chromosomes. Demonstration of constitutive heterochromatin by modified DNA/RNA hybridization technique
Author(s) -
Cervenka Jaroslav
Publication year - 1971
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.1399-0004.1971.tb00299.x
Subject(s) - constitutive heterochromatin , heterochromatin , centromere , biology , karyotype , trisomy , microbiology and biotechnology , chromosome , genetics , y chromosome , dna , gene
Treatment of standard human chromosomal preparations with NaOH and standard saline–citrate demonstrated constitutive heterochromatin. It is localized near the centromere or within the centromeric region in all except the Y chromosome. The technique was used for identification of G and Y chromosomes. In karyotypes of individuals with trisomy G1 (Down's syndrome) chromosomes number 21 (in the trisomy stage) possessed heterochromatin in different distribution from number 22 chromosomes; the latter having a distinctly dark stained centromere. The centromere, short arms, and proximal portion of the long arms of the Y chromosome were free of constitutive heterochromatin, which was demonstrated occupying the distal portion of the long arms. The extent of heterochromatin of the Y chromosome was identical with the heterochromatin demonstrated by quinacrine fluorochromes and responsible for the fluorescent “Y body.”