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

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

(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 46

Chromosome classification

1. Metacentric chromosome : p q 2. Submetacentric chromosome : p q 3. Acrocentric chromosome : satellite RNA

gene

( 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

(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

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

1. google NCBI link http://www.ncbi.nlm.nih.gov/ 2. OMIM

Duchenne muscular dystrophy search (enter )

3. link

Gene mapping locus Xp21.2

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

3. gene gene human beta globin Find (enter )

4. ...