Linkage

1
Linkage Recombination
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2
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3
AaBb
Gametes
Mendel
Linked gene
AB
Ab
aB
ab
4
(No Transcript)
5
(No Transcript)
6
(No Transcript)
7
(No Transcript)
8
WwGg X wwgg WwGg W_G_ W_gg wwG_ wwgg
Mendel
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9 3 3 1
9
PPLL X ppll
PpLl P_L_ P_ll ppL_ ppll
Linked gene
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15.58(296) 1 (19) 1.42 (27) 4.47 (85)
10
x
Parental type
0.446
p l P L
Recombination type
0.054
Recombination type
0.054
Parental type
0.446
11
P_L_0.699 (298) P_ll 0.051
(22) ppL_ 0.051 (22) ppll 0.199
(85)
427
12
Linkage group
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???????? Linked gene
Linked gene ????????????????? ? ???????? Linkage
group
????? Linkage group ????????????????????????????
1 ??? ??????????? n
13
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14
T.H.Morgan 1911
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• dumpy(dp)
• black body(bl)
• cinnabar eye(cn)

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15
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X
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16
Testcross
X
50
50
??????? ??????? 3 ???? complete linkage
17
X
1/8
1/8
1/8
1/8
1/8
1/8
1/8
1/8
18
??????? ??????? 3 ???? ???????????
1/8
1/2
1/2
1/2 cn
1/8
1/2
1/2
1/8
1/2 bl
1/2 cn
1/8
1/2
1/8
1/2
1/2 cn
1/8
1/2 dp
1/2
1/8
1/2 bl
1/2 cn
1/8
19
X
261
182
44
7
5
51
173
277
20
??????? ??????? 3 ???? Incomplete Linkage

26.1
1/2
1/2
1/2 cn
4.4
1/2
1/2
0.05
1/2 bl
1/2 cn
17.3
1/2
18.2
1/2
1/2 cn
0.07
1/2 dp
1/2
5.1
1/2 bl
1/2 cn
27.7
21
Double crossing over
22
C. Stern 1913
Attach segment of Y chromosome
Short X chromosome
x
23
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24
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25
?????????? ?????????????????? ???????????????????
??????????? ????? Recombinant ????????????????????
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Crossing over ???????????????????????????????????
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