Cytogenetics Flashcards
Components of chromosome
Negatively charged DNA, positively charged histone proteins （nucleoside: H2A, H2B, H3, H4)
Solenoid, solenoid loops
Role of chromosome
Transmit genetic information safely by preventing breakage.
Control gene expression
Chromosome territories
Regions of nucleus preferentially occupied by particular chromosomes.
Chromosomes with active genes are in the center, gene-poor ones are in periphery.
TADs
Topologically associating domains
Formed by architectural proteins.
Strong interactions (tads or sub tads)
Nuclear compartments-TADs-chromatin loops
Chromatin loops
Enhancer-promoter
Enhancer-silencer
Insulator-insulator
Chromosome metaphase
telomere
Centromere
Zeropoint
P arm(short)
Q arm (long)
Meiosis
Gametes formation
2 times of division
Haploid cell
Recombination
Crossing over
Meiotic metaphase I and II
Thestructural abnormalities
First and second meiotic division
Chromosome abnormalities
Translocation
Inversion
Duplication
Deletion
Ring
Trisomies (21)
Polyploidies
Autosome
Chromosomes exclude sex chromosomes
Pseudoautosomal Region
Overlapped region of X and Y chromosomes
Contains SRY, which determines the male sex.
Reciprocal translocation
The breakpoint disturbs a dominant gene might leads to illness
Robertsonian translocation
Lose the short arms
No phenotype
Have problems having children
Afrocentric chromosomes (13,14,15,21,22)
Structural abnormalities
Deletion
Insertion
Duplication
Inversion
Polyploid, aneuploidy
Turner (X)
21trisomy
18 trisomy Edward’s
Kleine felt er syndrome XXY
Copy number variations
3000genes are involved
Cytogenetic methods
FISH
NGS
CGH
Karyotyping
CGH
Analyze copy number variations
Reference dna needed
