4
QTL
1
2016/11/30 8:45-10:15
•
• quan4ta4ve trait
quan4ta4ve trait loci: QTL
QTL analysis; QTL mapping
Watanabe et al. (2005) Ann Bot. 95:1131
2
•
• locus QTL
•
•
•
•
•
• LOD
• (interval mapping)
• EM
• Composite interval mapping
3
vs.
1 R r
RR Rr rr
4
vs.
QTL QTL
QTL 1 QTL Q
q
52 87 48 72 32 68
QQ QQ Qq Qq qq qq
5
QTL
• gene
• locus loci
–
• quan4ta4ve trait locus
–
6
RR
rr Rr
qq Qq QQ
1.0
rr 100%
QTL
7
Frankham et al. (2002) Introduc4on to Conserva4on Gene4cs. Cambridge Univ. Press
8
East (1916) Gene4cs 1: 164
Frankham et al. (2002) Introduc4on to Conserva4on Gene4cs. Cambridge Univ. Press
corolla 9
A R
…
AARR aarr
AaRr F1
F2
a A
R r
F2
AA Aa aa
30 7 2
5 57 6
(RR)
(rr) (Rr)
1 8 29
(1-r)2/4
(1-r)2/4 r2/4
r2/4
r(1-r)/2
r(1-r)/2 r(1-r)/2
r(1-r)/2 {r2+(1-r)2}/2
A r=0.117 (13.33cM)
…
10
0 200 400 600 800 1000 1200
0.00.10.20.30.40.5
x
p(x)
0 200 400 600 800 1000 1200
0.00.10.20.30.40.5
0 200 400 600 800 1000 1200
0.00.10.20.30.40.5
0 200 400 600 800 1000 1200
0.00.10.20.30.40.5
AA Aa aa
? ? ?
? ? ?
QTL
qq Qq
? ? ?
(1-r)2/4
(1-r)2/4 r2/4
r2/4
r(1-r)/2
r(1-r)/2 r(1-r)/2
r(1-r)/2 {r2+(1-r)2}/2
QTL
11
F
2 16.237 9.372**
12 1.733
A a
A A a a
12.3cm 15.1cm 11.8cm 14.7cm
11.3cm 10.2cm 10.8cm 12.7cm
10.1cm 10.2cm 9.8cm 12.0cm 16.2cm 11.0cm
11.5cm
QTL
A
AA, Aa, aa 3
→
QTL
…
12QTL
QTL
QTL
QTL QTL
13
2 QTL
•
g i
e i
y i
gi: iyi: i ei: i
y
i= g
i+ e
ie
i~ N(0, σ
2)
0 σ2
y
i~ N(g
i, σ
2)
σ2 14
• phenotypic value
–
• genotypic value
–
• environmental effect
–
15
• x
μ σ2
(1)
(2)
(3)
f (x) = 1
2πσ
2exp −
(x − µ)
22σ
2%
&
' (
) *
-4 -2 0 2 40.00.10.20.30.4
x
f(x)
μ μ+2σ
μ-2σ
μ-4σ μ+4σ
16
• QTL
qq Qq QQ
μ
μ-a μ+d μ+a
a
d
QQ < qq a < 0
Qq QQ qq d < 0
a QTL d QTL
17
qq Qq QQ
μ-a μ μ+d μ+a
y
i~ N( µ + d, σ
2)
y
i~ N( µ + a, σ
2)
y
i~ N( µ − a, σ
2)
18
• i QTL QQ
y
i…
φ(y | µ,σ2) = 1 2πσ2exp −
(y− µ)2 2σ2
& ' (
) * +
p(yi)=
φ
(yi|µ
+ a,σ
2)QQ yi
y
i19
Qq QQ
y
1y
2y
3
y
4y
5y
6y
7y
8y
9y ,…, y9 L1
L
1= φ(y
1| µ − a,σ
2)φ(y
2| µ − a,σ
2)φ(y
3| µ + d,σ
2)φ(y
9| µ + a,σ
2)
QTL
→ QTL
→ QTL 20
2
H
1: QTL a ≠ 0 d ≠ 0
Qq QQ
y1 y2 y3y4 y5 y6y7 y8 y9
H
0: QTL a = 0 d = 0
y1 y2 y3y4 y5 y6y7y8 y9
L
1= φ(y
1| µ − a,σ
2)φ(y
2| µ − a,σ
2)φ(y
3| µ + d,σ
2)φ(y
9| µ + a,σ
2)
L
0= φ(y
i| µ,σ
2)
i=1 9
∏ max L
0 H0max L
1 H1maxL1/maxL0
N(μ, σ2)
QTL
21
LOD =log
10(maxL
1/maxL
0)
maxL
1/maxL
0QTL
H
1QTL
QTL
maxL
1/maxL
0H
0QTL
QTL
*
22
A B C D E
QTL
QTL
LOD
LO D
LOD =2H0 H1
100
QTL …
23
QTL
QTL
QTL
QTL
QTL
24
QTL
A Q B
r
Ar
P1
P2
F1 F2
A A
r
ABB B Q Q
a a
b q q
b
A a
B b
Q q
A A
B b
QTL
QQ (1- rA )(1- rB )/(1- rAB ) × (1- rA ) rB/ rAB Qq (1- rA )(1- rB )/(1- rAB ) × rA(1- rB )/rAB
rA rB/(1- rAB ) × (1- rA ) rB/rAB
qq rA rB /(1- rAB ) × rA(1- rB )/rAB A, B QTL
AABb QTL
…
? ?
25
A a
B b
Q q
A Q B
rAQ rQB
rAB
A, B QTL
F1
A-?-B :
1 2(1− rAB)
A-Q-B : 1
2(1− rA)(1− rB)
A-q-B : 1
2rArB A-?-B Q (1− rA)(1− rB) /(1− rAB)
A-?-B q rArB/(1− rAB)
A-?-b :
1 2rAB
A-Q-b : 1
2(1− rA)rB
A-q-b : 1
2rA(1− rB) A-?-b Q (1− rA)rB/ rAB
A-?-b q rA(1− rB) / rAB
P(X | Z) =P(X ∩ Z) P(Z)
:
QQ, Qq, qq 26Q q
AB q1 q2
Ab q3 q4
aB q4 q3
ab q2 q1
q1= (1− rA)(1− rB) /(1− rAB)
q2= rArB/(1− rAB)
QTL
q3= (1− rA)rB/ rAB q4= rA(1− rB) / rAB
QQ (pQQ) Qq (pQq) qq (pqq)
AABB q12 2q1q2 q22
AABb q1q3 q1q4+q2q3 q2q4
AAbb q32 2q3q4 q42
AaBB q1q4 q1q3+q2q4 q2q3 AaBb z1q1q2+z2q3q4 z1(q12+q22)
+z2(q32+q42)
z1q1q2+z2q3q4
Aabb q2q3 q1q3+q2q4 q1q4
aaBB q42 2q3q4 q32
aaBb q2q4 q1q4+q2q3 q1q3
aabb q22 2q1q2 q12
z1= (1− rAB)2/{(1− rAB)2+ rAB2} z2= rAB2/{(1− rAB)2+ rAB2}
27
…
y i
Qq QQ
i QTL QQ, Qq, qq yi
…
ϕiqq= p(yi| qq) =φ(yi|µ− a,σ2) = 1 2πσ2exp−
{yi− (µ− a)}2 2σ2 ' ( )
* + , ϕiQq= p(yi| Qq) =φ(yi| µ + d,σ2) = 1
2πσ2exp−
{yi− (µ + d)}2 2σ2 ' ( )
* + , ϕiQQ= p(yi| QQ) =φ(yi| µ + a,σ2) = 1
2πσ2exp −
{yi− (µ + a)}2 2σ2 ' ( )
* +
28 ,
yi
Qq QQ qq
AABb i
QTL QQ yi
ϕ
iQQA A
B b
? ?
p(QQ) = q
1q
3p
iQQp
iQQϕ
iQQ= q
1q
3φ (y
i| µ + a, σ
2)
QTL
29
EM
QTL
→
EM (expecta4on-maximiza4on)
(Dempster et al. 1977. J Roy Stat Soc. Ser B: 39: 1-39)
(E ) i QTL
z
iqq= ϕ
iqqp
iqq(ϕ
iqqp
iqq+ ϕ
iQqp
iQq+ ϕ
iQQp
iQQ)
z
iQq= ϕ
iQqp
iQq(ϕ
iqqp
iqq+ ϕ
iQqp
iQq+ ϕ
iQQp
iQQ)
z
iQQ= ϕ
iQQp
iQQ(ϕ
iqqp
iqq+ ϕ
iQqp
iQq+ ϕ
iQQp
iQQ)
pi** i QTL
(M ) ln L μ, a, b, σ2
ln L = { z
iqqln(ϕ
iqqp
iqq) + z
iQqln(ϕ
iQqp
iQq) + z
iQQln(ϕ
iQQp
iQQ) }
i=1 n
∑ + const
30
A B C D E
QTL
LOD
LO D
31
• CIM (composite interval mapping)
– QTL QTL
QTL
• MIM (mul4ple interval mapping)
– CIM QTL
QTL MIM
QTL
• Bayesian mul4ple QTL mapping
– :QTL:
QTL
GxE
32
IM
• IM 1 QTL
= QTL +
QTL1 2
Q
aQ
bQq QQ qq
QQ qq Qq
Qb Qa
33
IM
QTL
QTL A
QTL B
B A
34
CIM
= QTL +
= 1 QTL + QTL +
Qb
Qb
Σ
Qa(
QQ qq Qq
Σ
CIM
QQ qq Qq
35
CIM
QTL
QTL B
QTL A
B A
36
QTL
Qa Qb
QTL
LOD LOD
CIM IM
CIM > IM
…
QTL
QTL
37
SIM
CIM
1 22cM a=0.27
4.7%1 66cM a=0.43 11.6%
2 56cM a=0.29
6.2 %
IM CIM
100cM
2
55cM
QTL3 (a=0.3)
100cM
QTL1 (a=0.4)
1
25cM
QTL2 (a=0.35)
75cM
CIM 38
Mapmaker/QTL
ftp://ftp-genome.wi.mit.edu/distribution/software/newqtl/
QTL Cartographer (WinQTLCart)
http://statgen.ncsu.edu/qtlcart/ WinQTLCart GUI
IM, CIM, MIM 1
Qgene
http://coding.plantpath.ksu.edu/qgene/ eQTL
R/qtl
http://www.rqtl.org/
R QTL
2
Mul4mapper
hqp://www.rni.helsinki.fi/~mjs/
QTL
QTL
MAPL98
hqp://lbm.ab.a.u-tokyo.ac.jp/~ukai/mapl98.html
QTL
QTLBIM hqp://www.qtlbim.org/
R QTL
QTL
2
GxE
QTL
39
(1)
Ashikari et al. (2005) Science 309: 741-745Gene pyramiding:
1
SW2443
0.0
SW256
20.4
SW240
44.9
FSHB
55.3
SW942
56.3
S0091
62.9
SW395
65.0
SW766
69.9
SW1879
94.0
SWR308
129.7
Shear_value 0 5 10 15 20 25
chr2
QTL posi4on : 71.4cM (chromosome 2) QTL effect : a=0.67, d= 0.16
P1 P2
F1 F1
F2
) (2
42
• QTL
• -QTL-
• QTL QTL
• QTL
GxE
• QTL
43