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GEN I L.2 : Human chromosome & DNA
Structure of human chromosome
double strand helix DNA Nucleosome Chromatin fiber Chromatin in
extended form Condensed chromatin chromosome
Centromere
sister chromatid kinetochore microtubule chromatin
anaphase
Telomere (repetitive DNA sequence) TTAGGGn Telomere DNA : RNA
duplex TERT (Telomerase reverse transcriptase) Telomere
Telomere cell (cellular senescence) Telomerase therapy
Human chromosome o Heterochromatin inactive gene expression
Hypoacetylated Histone (histone deacetylation, HDAC) chromatin
Giemsa
o Euchromatin active gene expression Hyperacetylated Histone
chromatin Giemsa
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Types of banding
( 3 band Giemsa G-banded Quinacrine Q/R-banded confirm
centromere heterochromatin C-banded heterochromatin 1 9 16 Y Y
)
Methods of chromosome analysis
4 1. 2. 3. incubate 37 3 4. colchicine spindle fiber metaphase
5. Hypotonic saline 6. 7. karyotype
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(Denver classification) : Karyotyping
1. 21 22 2. Metacentric > submetacentric > acrocentric
3.
Human karyotyping
5 karyotype 7 A large metacentric 2 submetacentric B large
submetacentric C medium submetacentriccentric D medium acrocentric
E small submetacentric F small metacentric G small acrocentric
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Chromosome classification
1. Metacentric chromosome : p q 2. Submetacentric chromosome : p
q 3. Acrocentric chromosome : satellite RNA
gene
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( 6 )
Chromosome and gene location
( 7 7q31.1 7 q region 3 band 1 sub-band 1)
centromere p10 or q10
Idiogram
arm, region, band and sub-band gene ideogram
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(sex determination)
Barr body inactive X chromosome (X chromosome condensed
express)
Drumstick Barr body female neutrophil
inactive X chromosome Lyon Hypothesis Barr body X 16 X active X
condensed Heterochromatin Barr body
inactive X chromosome X active ( X active X active) Mosaic
Barr body Turner syndrome X Barr body
detect Y Y-specific DNA probe Y body Fluorescence body
(f-body)
Y buccal smears probe detect Y
Y X ( X X ) Y
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Gene Mapping Gene
( 11 gene human beta globin 11 Idiogram 11 gene beta globin
11p15.5 )
I. OMIM (Online Mendelian Inheritance in Man) NCBI (The National
Center for Biotechnology Information)
OMIM
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1. google NCBI link http://www.ncbi.nlm.nih.gov/ 2. OMIM
Duchenne muscular dystrophy search (enter )
3. link
Gene mapping locus Xp21.2
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4. ....
II. NCBI Map Viewer NCBI () genome mapping and
sequencing data genome genome
1. NCBI map viewer google link
http://www.ncbi.nlm.nih.gov/mapview/ 2. link human genome
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3. gene gene human beta globin Find (enter )
4. ...