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一、染色质 chromatin 二、染色体 chromosome 三、人类染色体的正常核型 the normal human karyotype PowerPoint Presentation
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一、染色质 chromatin 二、染色体 chromosome 三、人类染色体的正常核型 the normal human karyotype - PowerPoint PPT Presentation


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第二节 遗传的细胞基础. Cellular Basis of Inheritance. 一、染色质 chromatin 二、染色体 chromosome 三、人类染色体的正常核型 the normal human karyotype 四、染色体的多态性 chromosome polymorphism. 一、染色质( 1 ). Chromatin. ( 一 ) 染色质的分子结构 chromatin structure ( 二 ) 常染色质和异染色质 euchromatin and heterochromatin

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PowerPoint Slideshow about '一、染色质 chromatin 二、染色体 chromosome 三、人类染色体的正常核型 the normal human karyotype' - merrill-donaldson


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slide1

第二节 遗传的细胞基础

Cellular Basis of Inheritance

一、染色质 chromatin

二、染色体 chromosome

三、人类染色体的正常核型

the normal human karyotype

四、染色体的多态性

chromosome polymorphism

slide2

一、染色质(1)

Chromatin

(一)染色质的分子结构 chromatin structure

(二)常染色质和异染色质 euchromatin and heterochromatin

(三)性染色质 (sex chromatin)

X chromatin

Y chromatin

slide3

一、染色质(2)

Chromatin

1 Chemical components of chromatin:

DNA、protein、a little of RNA

?

2 Higher levels of chromatin structure:

Four levels of DNA packing

slide4

一、染色质(3)

Chromatin

Higher levels of chromatin structure: Four levels of DNA packing

“Beads-on-a-string” form of chromatin.

30 nm chromatin fiber of packed nucleosomes.

Section of chromosome in an extended form

Chromatid

slide5

一、染色质(4)

Chromatin

Cell

Histones

DNA

slide6

一、染色质(5)

Chromatin

核小体/nucleosome

slide7

一、染色质(6)

Chromatin

×7

nucleosome

DNA

×6

30 nm chromatin fiber of packed nucleosomes.

×40

Section of chromosome in an extended form

×5

Chromatid

×8400

slide8

一、染色质(7)

Chromatin

  • 染色质 chromatinInterphase。
  • 染色体 chromosomeM phase
slide9

一、染色质(8)

Chromatin

  • 常染色质(heterochromatin)和异染色质(euchromatin )
  • euchromatin: active, less compact。Heteromatin: repressed, concentrated 。

heterochromatin

euchromatin

slide10

一、染色质(9)

Chromatin

X染色质(X chromatin):female, interphase,

1μm body, heterochromatin

1949,Barr

Barr body

X body

slide11

一、染色质(10)

Chromatin

1961年,Lyon X 染色体失活假说 (Lyon hypothesis):

①only one of the two X-chromosomes is genetically active in female cells. The inactive X chromosome is silenced by packaging into transcriptionally inactive heterochromatin

②The choice of which X chromosome will be inactivated is random in placental mammals such as mice and humans, but once an X chromosome is inactivated it will remain inactive throughout the lifetime of the cell.

slide12

一、染色质(11)

Chromatin

?

剂量补偿效应

Dosage compensation effect

y y chromatin
Y染色质(Y chromatin):

一、染色质(12)

Chromatin

male

interphase

0.3 μm body,

Q-bright region of Y chromosome

slide14

二、染色体(1)

Chromosome

Structure, type and number

  • structure;:
  • 短臂 p
  • 长臂 q
  • 着丝粒 centromere
  • 主缢痕 primary constriction
  • 端粒 telomere
  • 次缢痕secondary constriction
  • 随体 satellite
slide15

二、染色体(2)

Chromosome

Metacentric chromosome: 1/2 -5/8

Submetacentric chromosome: 5/8 – 7/8

Acrocentric chromosome: 7/8 - telomere

Type

slide16

三、人类染色体的正常核型(1)

The normal human karyotype

(一)非显带核型

Karyotype without band

核型 karyotype

核型分析

karyotype analysis

slide17

三、人类染色体的正常核型(2)

The normal human karyotype

type methods

G banding trypsin, Giemsa

Q banding quinacrine mustard QM

R banding NaCl, Giemsa

T banding Heat, Giemsa

C banding NaOH, Giemsa

N banding AgNO3

q g r c
染色体显带Q-; G-; R-; C-;

三、人类染色体的正常核型(3)

The normal human karyotype

Q banding

G banding

Model of G- and R-banding

slide19

三、人类染色体的正常核型(4)

The normal human karyotype

karyotype with band

  • 界标 landmark
  • 区 region
  • 带 band
  • 1p35

高分辨显带

High resolution banding

slide20

三、人类染色体的

正常核型(5)

The normal human karyotype

slide21

三、人类染色体的正常核型(6)

The normal human karyotype

Number and structure

slide22

四、染色体的多态性(1)

chromosome polymorphism

女性染色体

46,XX

男性染色体46, XY

slide23

18号染色体

X染色体

Y染色体

13号染色体

21号染色体

四、染色体的多态性(2)

chromosome polymorphism

FISH

slide25
染色体命名

四、染色体的多态性(4)

chromosome polymorphism

人类细胞遗传学国际命名体制(ISCN, 1995)

(An International System for Human Cytogenetic Nomenclature)

p—短臂q—长臂

del—缺失dup—重复

i—等臂inv—倒位

rob—罗氏易位t—易位

der—衍生染色体ter—末端

46,XX,t(1;2)(p21;q23)

染色体总数,性染色体组成, 染色体变化

染色体号;臂号;区号;带号;(.亚带)

slide26
染色体表达式举例:

四、染色体的多态性(5)

chromosome polymorphism

47, XY, +21

45, X

46, XX, del(6)(p24)

47, XXY

45, XY, -14, -21, +rob(14;21)(q11;p11)