Identification of the Chromosomal Origin of Complex Structural Rearrangement Flashcards
T/F. Standard G banding can easily resolve complex rearrangement involving several chromosomes for example as found in some malignant tissues.
False. In these situations, DNA probes may be used in molecular in situ hybridisation procedures to label the specific components of an abnormal chromosome and so identify their origins.
These are repetitive probes which are centromere specific.
alphoid probes
These are probes which contain an insert large enough to provide a clear signal in the majority of metaphases.
cosmid or yeast artificial chromosome (YAC) probes
DNA probes can be also used to help to determine the precise position of a breakpoint in a chromosome translocation, and this can occasionally be invaluable in the identification of genes underlying specific conditions, such as the ____.
CHARGE association
T/F. The origin of smaller duplications & deletions may be easy to determine, particularly if the aberration is unbalanced & has arisen de novo .
False.
Chromosome paints may be made from ____, _____ or ____ sorted by a fluorescence activated cell sorting (FACS) machine.
chromosome - specific genomic libraries; single - chromosome somatic – cell hybrids; PCR - amplified chromosomes
T/F. Chromosome paints may also be made from abnormal chromosomes, w/c are sorted by FACS, amplified by PCR & painted onto normal metaphase chromosomes.
True
____ is a more recent development that enables several DNA probes to be used simultaneously.
Multicolour FISH (M - FISH)
Multicolor FISH has revealed that most de novo duplications are ____ or other forms of _____.
tandem duplications; intrachromosomal rearrangement
T/F. When applied to chromosome paints, it is possible, using different combinations of fluorescent dyes, to give each chromosome a distinctive colour & this can be useful in the analysis of complex chromosome rearrangements.
True.
