Karyotyping part 2 Flashcards
applied after cells have been arrested during cell division by a solution of colchicine
Giemsa
the inactive X chromosome in a female somatic cell
Barr body
Chromosomes 1-3 are largest with median centromere
GROUP A
Chromosome 4-5 are large with submedian centromere
Group B
Chromosomes 6-12 are medium sized with submedian centromere
Group C
Chromosomes 13-15 are medium sized with acrocentric centromere
Group D
Chromosomes 16-18 are short with median or submedian centromere
Group E
Chromosome 19-20 are short with median centromere
Group F
Chromosomes 21-22 are very short with acrocentric centromere
Group G
Similar to Group C
Chromosome X
Similar to Group G
Chromosome Y
is obtained with Giemsa stain following digestion of chromosomes with trypsin
This method will normally produce 300-400 bands in a normal, human genome
G-banding
tend to be heterochromatic, late-replicating and AT rich
Dark regions
is the reversed of G-banding
produces bands complementary to G-bands; induced by treatmentwith high temperature, low pH, or acridine orange staining; often used together with G-banding on human karyotype to determine whether there are deletions.
R-banding
Giemsa binds to consecutive heterochromatin, so it stains centromeres.
C-banding
is a fluorescent pattern obtained using quinacrine for staining. The pattern of bands is very similar to that seen in G-banding.
Q-banding
Visualize telomeres
T-banding
Silvernitrate stains the nucleolar organization region-associated protein. This yields a dark region where the silver is deposited, denoting the activity of rRNA genes within the NOR.
Silver staining
molecular cytogenetic technique used to simultaneously visualize all the pairs of chromosomes in an organism in different colors
Special Karyotyping
technique used to quantify the DNA copy number on a genomic scale.
Digital Karyotyping
where there are more than two sets of homologous chromosomes in the cells, occurs mainly inplants
Polyploidy
where one sexisdiploid, and the other haploid. Itis a common arrangement in the Hymenoptera,and in some other groups.
Haplo-diploidy
A process by which chromosomes replicate without the divisionof the cell nucleus,resulting in a polyploid nucleus. Also called endomitosis.
Endopolyploidy
is the condition in which the chromosome number inthe cellsisnot the typical number for the species.
Aneuploidy
from a truncated short arm on chromosome 5. The name comes from the babies’ distinctive cry, caused by abnormal formation of the larynx.
Cri du chat
from the loss of part of the short arm of chromosome1.
1p36 Deletion syndrome
50%of cases have a segment of the long arm of chromosome15
missing;a deletion of the maternal genes, example of imprintingdisorder
Angelman syndrome
50%of cases have a segment of the long arm of chromosome15 missing;a deletion of the paternal genes,example of imprintingdisorder.
Prader-Willi syndrome
