醫(yī)學遺傳學-染色體分組、核型與顯帶

醫(yī)學遺傳學——染色體分組、核型與顯帶110頁一、染色體分組(Chromosome

grouping)1-22號常染色體和X、Y性染色體形成24個基因連鎖群(linkage

group)組染色體號大小著絲粒位置次縊痕隨體說明A1-3最大1、3中2亞中1號長臂B4-5次大亞中C6-12X中等亞中9號長臂女16條男15條D13—15中等近端短臂末端E16—18小16中17、18亞中16號長臂F19—20次小中G21—22Y最小近端21號22號短臂末端女4條男5條女性：46，XX男性：46，XY二、染色體非顯帶核型（The

karyotype

of

non-banding

chromosome）非顯帶核型分析(karyotype

analysis)三、染色體顯帶(chromosome

banding)Q顯帶(Q

banding)G顯帶(G

banding)R顯帶(R

banding)T顯帶(T

banding)C顯帶(C

banding)N顯帶(N

banding)高分辯顯帶染色體(highresolution

banding

chromosome，HRBC)顯帶后的染色體呈現(xiàn)出獨特的帶紋即染色體帶型(banding

pattern)熒光染料氮芥喹吖因(quinacrine

mustard，QM)顯帶Q帶(Q

banding)反帶(reverse

band)鹽溶液處理，Giemsa染色，顯示的帶與G帶相反R帶(R

banding)T帶(T

banding)加熱，Giemsa染色，端粒特異性深染端粒(telomere)含有TTAGGG重復(fù)序列C帶(C

banding)NaOH堿處理再Giemsa染色，使著絲粒和1、9、16號次縊痕以及Y染色體長臂遠端的2/3的區(qū)段顯帶N帶(N

banding

pattern)AgNO3染色可使核仁組織區(qū)(NOR)銀染(Ag-NOR)受染的是與rDNA轉(zhuǎn)錄有關(guān)的一種酸性蛋白染色體的成份是核酸（DNA和RNA）和蛋白質(zhì)（組蛋白和非組蛋白）。染色體經(jīng)胰蛋白酶處理后，蛋白質(zhì)因被水解而使DNA分子中的堿基暴露，由于堿基中G/C和A/T的比例不同，對染料結(jié)合的程度不一樣

A/T堿基成份多，則Giemsa染料易與它結(jié)合而深染

G/C堿基成份多，則Giemsa染料不易與其結(jié)合而淺染。染色體縱軸上呈現(xiàn)明暗相間或深淺不一的帶紋技術(shù)原理G帶(G

banding)Chromosome

specimens

are

dealed

with

alkali

andTrypsase(parenzyme),

and

then

stained

by

Giemsa,

we

canobserve

the

alternate

with

bands

of

deep

color

and

light

c

under

the

microscope.A一禿頭來二蛇腰三似蝴蝶翩翩飄B四像鞭炮五黑腰C六號ｐ似小白臉C七蓋八下九細腰七(短臂遠端處深染)八(著絲粒下部深染)九(著絲粒下部淺染)C十號ｑ臂三深帶十一寬來十二窄十一(長臂近中段淺帶寬)十二(長臂近中段淺帶窄)C

X深帶一擔挑D十三下來十四中

十五深染頭上瞧十三下(下部深染)十四中(中部深染)十五上(上部深染)E十六深帶連著點十七長臂帶腳鐐十八人黑肚皮白F十九中間一點黑二十頭重腳輕飄G二十一似三角形二十二似羽毛球老Y貌似寶葫蘆四、人類染色體命名國際體制人類細胞遺傳學命名的國際體制An

International

System

for

HumanCytogeneticsNomenclature,

ISCN㈠界標(landmark)、區(qū)(region)、帶(bandLandmark：it

is

stable

andObvious(remarkable)

morphologicalcharacteristicson

chromosome.

Including：⑴the

end

of

two

arms,⑵centromere,⑶boundary

between

the

regions.Question：How

to

understand

that

thelandmark

band

is

the

first

band

of

the

nextregion？Region：the

region

between

the

twoadjacent(neighboring)

landmarks.

Thenomenclature

of

regions

begin

fromcentromere,

the

first

region

is

the

closestcentromere,

then

the

follows

are

named

thesecond

region,

the

third

region,

the

fourthregion

in

turn…Band：Chromosome

band

is

continuousand

without

non-band

areas.

Thenomenclature

of

band

also

begins

fromcentromere,

It

is

the

first

band,

the

secondband,

the

third

band,

the

fourth

band,

thefifth

band,

the

sixth

band

in

turn.

namedjust

like

region.㈡命名(Nomenclature)When

marking(indication)

a

band,

we

need

to

indicate

inturn(no

need

spacing

or

adding

punctuation):

①number

ofchromosome.

②number

of

arm.

③number

of

region.

④numbeof

band.For

example,1p35means

band

5,

region

3

of

short

arm

of

chromosome

114q32means

band

2,

region

3

of

long

arm

of

chromosome

141p31

1號染色體短臂3區(qū)1帶1q421號染色體長臂4區(qū)2帶界標是下一區(qū)的第一帶㈢高分辨顯帶染色體High

resolution

banding

chromosome，HRBC一套單倍體染色體帶紋僅

320條。染色體高分辨帶型可顯示550-850條帶紋，有助于發(fā)現(xiàn)更細微的染色體結(jié)構(gòu)異常1p31.1、1p31.2、1p31.3The

figure

shows

the

chromosome

1,

pleaseanswer

the

questions.⑴How

many

regions

are

theshort

arm

divided

into?

howmany

bands

does

each

regionscontain?⑵What

is

the

meaning

of

1q23?⑶According

to

the

rules

ofhuman

chromosomenomenclature,

write

the

bandname

of

the

short

arm

end.⑷

Label

1q32

on

the

figure

withan

arrows.⑵What

is

the

meaning

of

1q23?1q23

means

band

3,

region

2

of

longarm

of

chromosome

1.⑶According

to

the

rules

of

humanchromosome

nomenclature,

write

theband

name

of

the

short

arm

end.1p36⑷

Label

1q32

on

the

figure

with

anarrows.1q32⑴How

many

regions

are

the

short

arm

divided

into?

how

manybands

does

each

regions

contain?The

short

arm

of

No.1

are

divided

into

three

regions.the

first

region

has

three

bands.the

second

region

has

two

bands.the

third

region

has

six

bands.五、染色體的多態(tài)性(chromosomal

polymorphism)染色體的結(jié)構(gòu)、帶紋寬窄和著色強度等存在恒定的微小變異，染色體多態(tài)性主要在結(jié)構(gòu)異染色質(zhì)區(qū)，通常沒有明顯表型效應(yīng)或病理學意義1、Y的