Chromosome mapping

1
Chromosome mapping
???????????????????????????????????
Drosophila melanogaster X chromosome
2
Long wing, grey body
short wing, black body
testcross
Long wing, grey body
41
Palental type
41
Short wing, black body
9
Long wing, black body
Recombination type
9
Short wing, grey body
3
Long wing, grey body
short wing, black body
testcross
Long wing, black body
41
Palental type
41
Short wing, grey body
9
Long wing, grey body
Recombination type
9
Short wing, black body
4
Coupling ???? cis-configuration
?????????????????????????????????? wild type
??????? ???? mutant ???????
Repulsion ???? trans-configuration
?????????????????????????????????? wild type ???
mutant???? ???????
Recombination type ????????? 18 ???????
?????????????????? cis ???? trans
5
Stertevant
Recombination ????? Crossing over?????????????????
????????????? ????????????????????????????????
1 map unit 1 recombination
????????? recombination ?????????? 50
??? recombination 50 ???????????????????
??????
6
P
testcross
F1
25
Parental type
25
25
Recombination type
25
7
Two-point testcross
Drosophila melanogaster X chromosome
cu - normal wing cu - curled wing e - grey
body e - ebony body st - red eye
st - scarlet eye
8
Two-point testcross
testcross
426
42.6
Parental type
37.4
374
120
12
Recombination type
8
80
9
??????????????? cu ??? e
recombination between cu - e 12 8
20 map units
10
Three-point testcross

• phenotype ??????????????????????
  ????????????????? gametes ??????? parental type
• phenotype ???????????????????????
  ??????????????????? gametes ??????? double
  crossing over
• gene ??????? gamete ??????? double crossing over
  ?????????? gamete ??????? parental type
  ???????????????????????

11
cu e st/ cu e st x cu e st / cu
e st
36.6 38.0 2.4 3.0 8.9 10.5 0.2 0.4
366 380 24 30 89 105 2 4
cu e st / cu e st / cu e st / cu e
st/ cu e st / cu e st/ cu e st / cu e
st/
cu e st cu e st cu e st cu e st cu e
st cu e st cu e st cu e st
Parental type
Single crossing over between cu-st
Single crossing over between e-cu
Double crossing over type
1,000
100
12
Parental type
Double crossing over type
cu e st cu e st
cu e st cu e st
e cu st e cu st
13
0.4
0.2
????????????? gametes ??? Double crossing over
0.4 0.2 0.6
14
8.9
10.5
??????????????? e - cu Recombination S.C.O
between e - cu Recombination D.C.O (
8.9 10.5) (0.4 0.2) 20 map units
15
2.4
3.0
??????????????? cu - st Recombination S.C.O
between cu - st Recombination D.C.O
( 2.4 3.0) (0.4 0.2) 6 map units
16
20 m.u.
6 m.u.
cu
st
e
17
Interference
????????????????????? crossing over
??????????????????? ?????????????????? crossing
over ??????????????????? ??????????????????
Interference 1 -
18
Coefficient of Coincidence
????????????????????????????? crossing over
???????
Coefficient of Coincidence


Interference 1 - Coefficient of Coincidence
19
cu e st/ cu e st x cu e st / cu
e st
0.366 0.38 0.024 0.03 0.089 0.105 0.002 0.004
360 380 24 30 89 105 2 4
cu e st / cu e st / cu e st / cu e
st/ cu e st / cu e st/ cu e st / cu e
st/
cu e st cu e st cu e st cu e st cu e
st cu e st cu e st cu e st
Parental type
Single crossing over between cu-st
Single crossing over between e-cu
Double crossing over type
1,000
1
20
Observed Double Crossing Over Frequency 0.004
0.002 0.006
Expected Double Crossing Over Frequency
(6/100) x (20/100) 0.06 x 0.2 0.012
21
Interference 1 -
1 - 0.006/0.012 0.5
???? ????????? crossing over ???????????????????
?????????????? crossing over ??????????????? ????
50
Interference 1 ??????????? ????????? crossing
over ??????????????????? ?????????????? crossing
over ???????????????????
Interference 0 ??????????? ????????? crossing
over ??????????????????? ?????????????????
crossing over ???????????????????