Chapter 6 Chromosome and Linkage Group

8

1P.C. Winner, G.I. Hickey & H.L. Fletcher,Instant Notes in Genetics, BIOS Scientific Publishers Limited,1998.12.2 199963 20023

4 3200215 200016 200047 200188 20019

The structure of this chapter

(Law of linkage and crossing-over)2335000

MorganBridgesF29:3:3:1W.Bateson R.C.Punnet,1906

Bateson-Punnet P: F1: (O) (E)F2: 4831 9 3910.5390 3 1303.5393 3 1303.51338 1 434.5 6952 2 = (Oi-Ei)2/Ei=3371.58 df=4-1=3, 2 >2 0.05=7.822 >>2 0.01=11.35 F2

P: F1: (O) (E)F2: 226 9 235.8 95 3 78.5 97 3 78.5 1 1 26.2 419 2 = (Oi-Ei)2/Ei=32.4 df=4-1=3, 2 >2 0.05=7.822 >2 0.01=11.35 OE.

F2Batson(coupling phase)(repulsion phase)19121910

LinkageP: (BBVV) (bbvv) F1:(BbVv) (BbVv) (bbvv) (BbVv) : (bbvv) =1 : 1 (BbVv) :(bbVv) :(Bbvv):(bbvv)=1:1:1:1 F2

(BbVv) (bbvv) (BbVv) : 0.42 (bbVv) : 0.08 (Bbvv) : 0.08 (bbvv) : 0.42 F2

BVbvBV,bv 1.(linkage): 2. (Complete linkage):P: (BBVV) (bbvv)

F1: (BbVv) (bbvv)

(BbVv) : (bbvv) =1 : 1

3. (Incomplete linkage) (BbVv) (bbvv)

: : : (BbVv) (bbVv) (Bbvv) (bbvv)

4.(coupling phase and repusion phase) Bateson()(coupling phase), )(repusion phase):abAB(AB/ab);(Ab/aB)

5.(Recombination) (Recombination) (recombinants)6. (recombination frequencyRF) F11:1:1:1(recombination frequencyRF)

:RF=16%

(C)(c);(Sh)(sh)ShCCSh/CSh X csh/csh:

97%3%RF50%1:1:1:1RF1:1:1:1

(linkage group)(linkage group)(n)4I1IIIIIV 234233.52323

(crossing over) Janssens, 1909chiasmatype hypothesis) 1. (chiasma)(crossing over).

2.

(Law of linkage and crossing-over) .

(interchromosomal recombination)(intrachromosomal recombiation)

22CDCMorgan()

The law of HaldaneJBSHaldane::(SC)SC

double crossingover double crossingover:AB() () ABC() 3

()(1911)() 3 3abcabbcacAHSturtevant

(gene mapping) (chromosome map)(linkage map)(genetic map)()(map distance) (map distance)1%()(map unitmu)THMorgan (centimorgan, cM)l cM=l%%

(two-point testcross)1. bi-w: 5.3cM w-y: 1.1 cM (1) w-y-bi (2) y-w-bi y-bi: 5.5 cM2.

(three-point testcross)Sturtevant33abc/+++3abc/abc3wybi3

ec-ct18.4%eccvcvct10.2%+8.4%=18.6%=/=18.4%?eccteccvcvct?? (ecct)ecctcv

8(+++ec ct cv)eccvcvctecctecct218.4%+2x0.1%-18.6%(eccvcvct)ecct18.6cM eccvcvct836

(interferenceI) ecct10.2%X8.4%=0.86% (5+3)/5318=0.15%(interferenceI)(chromommeintedepence) (positive interference) (negative interference)

(Chromatid interference) 121

1. (chromatid interference)4 1:2:12. 3. 2324131450%

(coefficient of cincidence) , (coefficient of coincidenceC)

I=l-CC=lI=0, I=16 C=0.15%/ 0.86% =0.17I=1-C=1-0.17=0.8383%83%

41/2100%1/2x100%=0.50 ?

RFmax=8/16=50%

1/4;2/4;1/41:2:11:2:150%100%AB50%41150%

1. 2. : 3. 4.

7

:(A)(a)(:)(ascus)(2n)48

(tetrad): (tetrad analysis):(ordered tetrad):

4(tetrad)8;(orded tetrad)

:1.(locus)2.3.(gene conversion)4.434

(centromere mapping) :(first-division segregation)MI;(second-division segregation)MIIAa

()( first-division segregation , MI) Aa2nnnMI

()( Second-division segregation , MII) Aa

()(Centromere mapping) :(Iysine)(lys+)(lys )

64(spore pairs)

2.

3.n

4.a

5.an6.

(cM)3300cMl cM1000kb

()(mapping function)?(mapping function) (Poisson distribution) (p 0) Poisson

Poisson:

x=012m=: 0(RF)

(poisson distribution), x:

x=1,2,3, ; m:

f(x>0)=1 - f(0) =1 - e-m, , :

x(cM)mx=m/2(RF)mmm

RFm RFmm 1.mmRFRF: m=0.05 e-m=0.95, RF=(1-0.95)/2=2.m3.mRF(1-0)/2=50%, 50%RF()m RF

:27.5%?0.275=(1-e-m)/2 1 - e-m=0.55 e-m=1 - 055=045 m=0.80.84m1/20.440cM

410

:1.0,02. 0%-50%5050% Xyr57.6cMy-r50%

30

genetic map gene linkage map,1cM1000kbphysical map DNAsequence tagged site,STSSTSMbkbSTSphysical mapYACDNAMbkb

mRNAmRNADNA1%-5%DNA10%mRNAcDNAESTEST100-300bpcDNAmRNAmRNAcDNAEST

Wilson19111968Donahueuffy1,.1973

(pedigree method)

grandfather method)

1. a b PEG 2.banding pattern3.

DNADNADNA

1. cDNADNA2.in situ hybridization DNARNADNAfluorescence in situ hybridization, FISH,DNA

3.PCRin situ PCR PCRPCRDNADNAPCR PCRPCRDNA;PCR;

YXX30bp 3.4-3.570%30%: 22A+XYhuman genome project, HGP)19912003

X

20%-25%

1OoSs4 OS23 oS83 Os85 os19 O-s2O-S 4 3co CO CCooccoo ccoo68204o-c

4 AABBaabb AaBbaabb AaBb aabb aaBb aabb (1-p) p p (1-p)1p= 2p= 3p=5pxal 7416pxal10%412

6 pxpxalPx.Alpx al7 abcABCF1 abc 211 ABC 209 ABC 212 AbC 2081 2

8O(oblate=flattened fruit),P(peach=hairy ruit)S(compound inflorescence)F1 +++ 73 ++s 348 + P+ 2 +Ps 96 o++ 110 o+s 2 oP+ 306 oPs 631 2 3 4

9 60%/+++/1000 10. 6-2111. 2-3