Deletion of specific sequences or modification of centromeric chromatin are responsible for Y chromosome centromere inactivation.
Stable dicentric chromosomes behave as monocentrics because one of the centromeres is inactive. The cause of centromere inactivation is unknown; changes in centromere chromatin conformation and loss of centromeric DNA elements have been proposed as possible mechanisms. We studied the phenomenon of inactivation in two Y centromeres, having as a control genetically identical active Y centromeres. The two cases have the following karyotypes: 45, X/46,X,i(Y)(q12) and 46,XY/47,XY,+t(X;Y) (p22.3;p11.3). The analysis of the behavior of the active and inactive Y chromosome centromeres after Da-Dapi staining, CREST immunofluorescence, and in situ hybridization with centromeric probes leads us to conclude that, in the case of the isochromosome, a true deletion of centromeric chromatin is responsible for its stability, whereas in the second case, stability for its stability, whereas in the second case, stability of the dicentric (X;Y) is the result of centromere chromatin modification.
Maraschio
P
P
Biologia Generale e Genetica Medica, Università di Pavia, Italy.
Zuffardi
O
O
Caiulo
A
A
Dainotti
E
E
Piantanida
M
M
Rivera
H
H
Tupler
R
R
D000293:Adolescent; D000328:Adult; D002503:Centromere / Q000502:physiology*; D002843:Chromatin / Q000502:physiology*; D002871:Chromosome Banding; D002872:Chromosome Deletion; D004247:DNA / Q000032:analysis; D004303:Dosage Compensation, Genetic; D005260:Female; D005347:Fibroblasts / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D006801:Humans; D007006:Hypogonadism / Q000235:genetics; D008607:Intellectual Disability / Q000235:genetics; D007621:Karyotyping; D017880:Limb Deformities, Congenital; D008214:Lymphocytes / Q000378:metabolism; D008297:Male; D009693:Nucleic Acid Hybridization; D014998:Y Chromosome
D002843:Chromatin; D004247:DNA