细胞核和染色体

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一、中期染色体的形态结构
Structure of metaphase chromosome
1. Centromere(着丝粒) & Kinetochore（动粒）
Centromere（着丝粒）: Highly repeated DNA+Kinetochore（动粒）
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着丝粒3个结构域
配对结构域
Proteins associated with the centromere have been identified using antibodies from scleroderma patients
CENP proteins
CENP-A
centromere-specific histone
CENP-B
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二、染色体DNA的3种功能元件
Three functional elements in chromosomal DNA
Three functional elements are required for replication and stable inheritance of chromosomes
division and not during all stages of the cell cycle. They are in their most condensed form during
metaphase (中期)when the sister chromatids（姐妹 染色单体） are attached.
2、中央结构域（ Central domain ） 位于着丝粒结构域的下方。其中含有高度重复的卫星DNA。
3、配对结构域（ Pairing domain ） 位于着丝粒结构的内层，中期两条染色单体在此处相互连结。 用ACAs发现鉴定出来的着丝粒蛋白CENP主要有6种，即：CENP-A至F。
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Centromeric proteins
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Metaphase chromosome:
The two replicated daughter DNAs are encased in chromosomal proteins forming sister chromatids, which are held together at their centromere.
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Section 4 chromosome (染色体)
Q: What is the chromosome?
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Chromosome(染色体):
Q: Can you see Adchitvrsiosomimoanetipnproowicnieltlsdbs,uertpihnaegcktahgeecdelcuml hnircdoreomrsolcisgoohpmte?es
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构成染色体DNA的三种关键序列（key sequence）
✓ autonomously replicating DNA sequence,ARS （自主复制DNA序列）
✓ centromeric DNA sequence, CEN（着丝粒DNA序列） ✓ telomeric DNA sequence, TEL （端粒DNA序列）
Telomeres are crucial to the life of the cell. They keep the ends of the various chromosomes in the cell from accidentally becoming attached to each other.
二．Functional elements
染色体DNA的三种功能元件
三．Karyotype and chromosome banding 核型与染色体显带
四．Giant chromosome 巨大染色体
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一、中期染色体的形态结构
Structure of metaphase chromosome Chromosomes are detected only occur during cell
位于染色体DNA的两端, 为一富含GC的短串联重复序列DNA组成 ，进 化上高度保守。
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Telomeres
The telomeres of humans consist of as many as 2000 repeats of the sequence: 5' TTAGGG 3'.
5'...TTAGGG TTAGGG TTAGGG TTAGGG TTAGGG TTAGGG..3' 3'...AATCCC AATCCC AATCCC AATCCC AATCCC AATCCC..5'
binds central domain satellite DNA
CENP-C
binds kinetochore
CENP-D
binds kinetochore
CENP-E
kinesin-like motor, involved in
chromatid segregation
CENP-F binds kinetochore
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NOR（Nucleolar organizer regions） :
The NOR is responsible for the formation of the nucleolus during telophase and is also the site of ribosomal RNA synthesis.
See P343, Tab 10-6
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ChromosomБайду номын сангаас Numbers
Is there a correlation between chromosome number and complexity of the organism?
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Chromosome 染色体
一．Morphology of the metaphase chromosome中期染色体的形态结构
tightly enough that we are able to visualize distinct chromosomes under the light microscope 分裂期染色质凝集而成的棒状结构 。
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Chromosome number,size,and shape at metaphase are species specific
between two sister chromatids
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Satellite DNA(FISH image)
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Centromere & Kinetochore
The structure of a human CEN
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着丝粒的结构
1、动粒结构域（kinetochore domain） 位于着丝粒的表面，包括 内板(inner plate) 中间间隙(middle space),innerzone 外板(outer plate) 纤维冠(fibrouscorona)
与间期核仁的形成有关
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Telomeres 端粒
Telomeres are the physical ends of linear eukaryotic chromosomes.
They consist of tandem repeats of a short (6-8 bp) sequence that is highly conserved through evolution.
细胞核特定染色体的次缢痕处，含有rRNA基因的一段染色 体区域，与核仁的形成有关，故称为核仁组织区。
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NOR（Nucleolar organizer regions） :
Not all chromosomes in a genome have NORs, but several of them may have.
1.Centromere（着丝粒） Primary constriction
主缢痕
5.Telomere（端粒）
Human chromosome No.14
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NOR（Nucleolar organizer regions） :
NOR is a chromosomal region around which the nucleolus forms. This region is the particular part of a chromosome that is associated with a nucleolus after the nucleus divides. The region contains several tandem copies of ribosomal RNA genes.
INCENP proteins
INCENP-A sister chromatid association INCENP-B sister chromatid association
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一、中期染色体的形态结构
A typical mitotic chromosome at metaphase 4.Satellite（随体 ） 2.secondary constriction（次缢痕 ） 3.nucleolar organizing region, NOR（核仁组织区）
细胞核和染色体
Main contents
Section 1 nuclear envelope and nuclear pore complex
Section 2 chromatin Section 3 chromatin structure and gene
activation Section 4 chromosome Section 5 nucleolus Section 6 nuclear matrix