Use of an alphoid satellite sequence to locate the X chromosome automatically, with particular reference to identification of the fragile X.
An alphoid DNA sequence primarily located on the X chromosome was labeled with biotin and hybridized in situ to preparations of metaphase chromosomes derived from fragile X-affected individuals; hybridization sites were detected immunologically. Labeled X chromosomes were located automatically in digitized images of metaphase cells by searching for the concurrence of a pronounced peak in the longitudinal density profile with the centromere in medium-sized chromosomes having a suitable centromeric index. Approximately 70% of the X chromosomes were detected by a simple classifier; this rate is similar to the automatic classification rate obtained with G-banded metaphases. The frequency of detection of the fragile X site obtained when scored directly from the microscope using this new preparation technique did not differ significantly from the frequency obtained in the same sample by means of a conventional technique. The frequency obtained by visual scoring of digitized images was slightly higher, but not significantly so.
Fantes
J
J
MRC Human Genetics Unit, Edinburgh, Scotland, UK.
Gosden
J
J
Piper
J
J
D002874:Chromosome Mapping; D004276:DNA, Satellite; D005600:Fragile X Syndrome / Q000175:diagnosis* / Q000235:genetics; D006801:Humans; D007091:Image Processing, Computer-Assisted; D009693:Nucleic Acid Hybridization; D012729:Sex Chromosome Aberrations / Q000175:diagnosis*; D014960:X Chromosome / Q000648:ultrastructure*
D004276:DNA, Satellite