1. Jeffrey Ross-Ibarra
@jrossibarra • www.rilab.org
Plant Sciences • Center for Population Biology • Genome Center
University of California Davis
Embiggening DNA: the role of plant genome
size in intra- and interspecific adaptation
2. Abizar at English Wikipedia [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0) or
GFDL (http://www.gnu.org/copyleft/fdl.html)], via Wikimedia Commons
Genome Size (bp)
3. By Nr387241 - Own work, CC BY-SA 3.0, https://
commons.wikimedia.org/w/index.php?
curid=14945255
Mycoplasma (0.0006Gb)
Abizar at English Wikipedia [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0) or
GFDL (http://www.gnu.org/copyleft/fdl.html)], via Wikimedia Commons
Genome Size (bp)
4. By Gőtehal.jpg: Mathae derivative work: Bff (Gőtehal.jpg) [CC BY 2.5 (http://
creativecommons.org/licenses/by/2.5), CC-BY-SA-3.0 (http://
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copyleft/fdl.html)], via Wikimedia Commons
Protopterus (130Gb)
By Nr387241 - Own work, CC BY-SA 3.0, https://
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curid=14945255
Mycoplasma (0.0006Gb)
Abizar at English Wikipedia [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0) or
GFDL (http://www.gnu.org/copyleft/fdl.html)], via Wikimedia Commons
Genome Size (bp)
5. Genlisea (0.065Gb)
By Michal Rubeš [CC BY 3.0 cz
(http://creativecommons.org/
licenses/by/3.0/cz/deed.en)], via
Wikimedia Commons
By Gőtehal.jpg: Mathae derivative work: Bff (Gőtehal.jpg) [CC BY 2.5 (http://
creativecommons.org/licenses/by/2.5), CC-BY-SA-3.0 (http://
creativecommons.org/licenses/by-sa/3.0/) or GFDL (http://www.gnu.org/
copyleft/fdl.html)], via Wikimedia Commons
Protopterus (130Gb)
By Nr387241 - Own work, CC BY-SA 3.0, https://
commons.wikimedia.org/w/index.php?
curid=14945255
Mycoplasma (0.0006Gb)
Abizar at English Wikipedia [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0) or
GFDL (http://www.gnu.org/copyleft/fdl.html)], via Wikimedia Commons
Genome Size (bp)
6. By alpsdake - Own work, CC0, https://commons.wikimedia.org/w/index.php?
curid=12228596
Paris (150Gb)
Genlisea (0.065Gb)
By Michal Rubeš [CC BY 3.0 cz
(http://creativecommons.org/
licenses/by/3.0/cz/deed.en)], via
Wikimedia Commons
By Gőtehal.jpg: Mathae derivative work: Bff (Gőtehal.jpg) [CC BY 2.5 (http://
creativecommons.org/licenses/by/2.5), CC-BY-SA-3.0 (http://
creativecommons.org/licenses/by-sa/3.0/) or GFDL (http://www.gnu.org/
copyleft/fdl.html)], via Wikimedia Commons
Protopterus (130Gb)
By Nr387241 - Own work, CC BY-SA 3.0, https://
commons.wikimedia.org/w/index.php?
curid=14945255
Mycoplasma (0.0006Gb)
Abizar at English Wikipedia [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0) or
GFDL (http://www.gnu.org/copyleft/fdl.html)], via Wikimedia Commons
Genome Size (bp)
8. Lynch and Connnery (2003) Science Lefébure et al. (2017) Genome Research
genome size (pg)dN/dS
surface
subterannean
9. Whitney et al. (2010) Evolution
Contrast in Ne
ContrastinGenomeSize
10. Seed Weight (+)
Leaf Size (-)
Knight (2005) Ann Bot
Genome Size (2C pg)
Seed Weight
GenomeSize(2Cpg)specificleafarea
Whitney et al. (2010) Evolution
Contrast in Ne
ContrastinGenomeSize
11. Kang et al. (2015) Sci Reports
GenomeSize
SoilNitrogen
Seed Weight (+)
Leaf Size (-)
Knight (2005) Ann Bot
Primulinaspp.
Genome Size (2C pg)
Seed Weight
GenomeSize(2Cpg)specificleafarea
Whitney et al. (2010) Evolution
Contrast in Ne
ContrastinGenomeSize
12. Larger genomes adapt differently:
the “functional space” hypothesis
Intraspecific adaptive evolution
of genome size in maize
13. Larger genomes adapt differently:
the “functional space” hypothesis
Intraspecific adaptive evolution
of genome size in maize
14. The small differences in genome size within
species seem generally to be of minor
importance compared to other components of
plant fitness. Šmarda & Petr Bureš (2010) Preslia
The ‘plastic genome’ seems to be an idea
rather than a defendable scientific
hypothesis; intraspecific variation is less
frequent than presently thought. Greilhuber (1998) Ann Bot
19. Domestication
10,000BP
Takuno et al. (2015) Genetics
Lowland
K=3K=4
Highland Lowland Highland
Mesoamerica South America
Lowland
A B
K=2K=3K=4
Highland Lowland Highland
Mesoamerica South America
Altitude
21. Domestication
10,000BP
Mexican Highlands
6,000BP
S. American lowlands
6,000BP
Takuno et al. (2015) Genetics
Lowland
K=3K=4
Highland Lowland Highland
Mesoamerica South America
Lowland
A B
K=2K=3K=4
Highland Lowland Highland
Mesoamerica South America
Altitude
22. Domestication
10,000BP
Mexican Highlands
6,000BP
S. American lowlands
6,000BP
Andes
4,000BP
Takuno et al. (2015) Genetics
Lowland
K=3K=4
Highland Lowland Highland
Mesoamerica South America
Lowland
A B
K=2K=3K=4
Highland Lowland Highland
Mesoamerica South America
Altitude
26. altitude
GenomeSize(Mb) 77 landraces
S. America
Mexico
teosinte
95 mexicana
altitude
P = µ + alt ⇤ A + g + "
g ⇠ MV N (0, VAK)
" ⇠ N (0, V✏)
Genome Size Altitude
Additive
Component
Berg and Coop (2014) Plos Gen
27. altitude
GenomeSize(Mb) 77 landraces
S. America
Mexico
teosinte
95 mexicana
altitude
P = µ + alt ⇤ A + g + "
g ⇠ MV N (0, VAK)
" ⇠ N (0, V✏)
Genome Size Altitude
Additive
Component
Berg and Coop (2014) Plos Gen
landraces
landraces
Kinship
Additive
Genetic Var.
28. altitude
GenomeSize(Mb) 77 landraces
S. America
Mexico
teosinte
95 mexicana
altitude
P = µ + alt ⇤ A + g + "
g ⇠ MV N (0, VAK)
" ⇠ N (0, V✏)
Genome Size Altitude
Additive
Component
Berg and Coop (2014) Plos Gen
landraces
landraces
Kinship
Additive
Genetic Var.
-110Kb/m
-260Kb/m
29. Rosado et al. (2005) Maize
Genetics Newsletter (shh, secret)
Knob180
KnobTR1
Maize TEs
Sorghum TEs
Jiao et al. (2017) Nature
copy
number
30. Rosado et al. (2005) Maize
Genetics Newsletter (shh, secret)
Knob180
KnobTR1
Maize TEs
Sorghum TEs
Jiao et al. (2017) Nature
copy
number
31. Rosado et al. (2005) Maize
Genetics Newsletter (shh, secret)
Knob180
KnobTR1
Maize TEs
Sorghum TEs
Jiao et al. (2017) Nature
copy
number
55. 1. Selection for earlier flowering leads to smaller genomes
across altitudinal gradients in maize and teosinte
2. Genome size is a quantitative trait that can affect fitness,
and observed intraspecific variation may be adaptive
3. Selection on genome size likely impacts the evolution of
individual repeat classes
56. Intraspecific adaptive evolution
of genome size in maize
Larger genomes adapt differently:
the “functional space” hypothesis
https://github.com/RILAB/AJB_MutationalTargetSize_GenomeSize
72. Beissinger et al. 2016 Nature Plants
nucleotidediversity
distance to nearest substitution (cM)
prediction: bigger genomes have few hard sweeps
73. Beissinger et al. 2016 Nature Plants
nucleotidediversity
distance to nearest substitution (cM)
prediction: bigger genomes have few hard sweeps
74. Sattah et al. 2011 PLoS Gen.
Williamson et al. 2014 PLoS Gen
Hernandez et al. 2011 Science
Beissinger et al. 2016 Nature Plants
L = 2,500 Mbp
75. Sattah et al. 2011 PLoS Gen.
Williamson et al. 2014 PLoS Gen
Hernandez et al. 2011 Science
Beissinger et al. 2016 Nature Plants
L = 2,500 Mbp
diversity
L = 220 Mbp
76. Sattah et al. 2011 PLoS Gen.
Williamson et al. 2014 PLoS Gen
Hernandez et al. 2011 Science
Beissinger et al. 2016 Nature Plants
L = 2,500 Mbp
distance from substitution
L = 3,100 Mbp
L = 130 Mbp
diversity
L = 220 Mbp
77. M T G P H R L
GGTCGAC ATG ACT GGT CCA CAT CGA CTG TAG
78. M T G P H R L
GGTCGAC ATG ACT GGT CCA CAT CGA CTG TAG
M T N P H R L
GGTCGAC ATG ACT GAT CCA CAT CGA CTG TAG
structural
change to protein
79. M T G P H R L
GGTAAAC ATG ACT GGT CCA CAT CGA CTG TAG
GG—-AC ATG ACT GGT CCA CAT CGA CTG TAG
regulatory change to
expression
80. Hufford et al. 2012 Nat. Gen.
Chia et al. 2012 Nat. Gen
maizeteosinte
prediction: bigger genomes have more intergenic adaptation
81. Hufford et al. 2012 Nat. Gen.
Chia et al. 2012 Nat. Gen
maizeteosinte
prediction: bigger genomes have more intergenic adaptation
82. Hufford et al. 2012 Nat. Gen.
Chia et al. 2012 Nat. Gen
maizeteosinte
prediction: bigger genomes have more intergenic adaptation
5-10% selected regions
do not include genes
90. Fedoroff 2012, Wang and Dooner 2006
Homologous (loop) 34%
No pairing 20%Nonhomologous 46%
Maguire 1966 Genetics
91. Pyhäjärvi et al. 2013 GBEFigure S4 LD in chromosome 9 among mexicana populations based on SNPs with minor
allele frequency >0.1.
Inv9d
Inv9e
92. Inv4n
macrohairs,
anthocyanin
Hufford et al. 2013 PLoS Genetics
Pyhäjärvi et al. 2013 GBEFigure S4 LD in chromosome 9 among mexicana populations based on SNPs with minor
allele frequency >0.1.
Inv9d
Inv9e
93. Inv4n
macrohairs,
anthocyanin
Hufford et al. 2013 PLoS Genetics
Pyhäjärvi et al. 2013 GBEFigure S4 LD in chromosome 9 among mexicana populations based on SNPs with minor
allele frequency >0.1.
Inv9d
Inv9e
Pyhäjärvi et al. 2013 GBE
94. 4% of B73 absent
~8% absent
%readsunmappedreads
Gore et al. 2009 Science
Chia et al 2012 Nat Gen
95. 4% of B73 absent
~8% absent
30% of the low copy sequence
absent from reference genome
%readsunmappedreads
Gore et al. 2009 Science
Chia et al 2012 Nat Gen
✓⇡
n 1X
i=1
1
i
= S
θπ ~ 8% pairwise diff
1-S% pan-genome in ref
100. • Genome size is the best quantitative trait in the galaxy, and may itself be
an adaptive trait
• Selection on genome size may impact repeat evolution
• Large genomes may have a larger mutational target — more “functional
space” — and thus adapt via soft sweeps and noncoding variation
• Consider genome size when designing and interpreting studies of plant
adaptation
Concluding Thoughts on
Embiggening Plant DNA
Kew C-Value Database
101. Acknowledgements
USDA
Ed Buckler
Doreen Ware
U Missouri
Patrice Albert
Jim Birchler
U Georgia
Kelly Dawe
Cornell
Kelly Swarts
UC Davis
Jeremy Berg
Graham Coop
Mark Grote
Juvenal Quesada
Plant Genome
Research Program
HiLo
Lab Alumni
Tim Beissinger (USDA-ARS, Mizzou)
Paul Bilinski
Kate Crosby (Monsanto)
Matt Hufford (Iowa State)
Tanja Pyhäjärvi (Oulu)
Shohei Takuno (Sokendai)
Joost van Heerwaarden (Wageningen)
Jinliang Yang (U Nebraska-Lincoln)
103. ● ●
●
●
0
5
10
15
20
25
200 400 600 800 1000
Genome Size (Mb)
OpenChromatinSize(Mb)
Genome_feature
●
Exon
Intergenic
Proximal
Total_open_chromatin
A
●
●
75%
80%
85%
90%
95%
500 1000 1500 2000 2500
Genome Size (Mb)
%Non−exonicOpenChromatin
Species
●
●
●
●
●
●
●
●
●
Arabidopsis
Brachypodium
Cotton
Maize
Medicago
Millet
Rice
Sorghum
Tomato
Tissue
●
●
Callus
Fiber
Fruit
Leaf
Root
Seedling
Shoot
B
Genom
Functional
Space
Functional
Space
Soft Sweeps
Intergenic
Adaptation
Functional
Space
Hard sweeps
106. hard sweep
Figure 1.
Phenotypes. a. Maize ear showing the cob (cb) exposed at top. b. Teosinte ear with the rachis
internode (in) and glume (gl) labeled. c. Teosinte ear from a plant with a maize allele of tga1
Wang et al. Page 10
NIH-PAAuthorManuscriptNIH-PAAuthorManuscript
Wang et al. 2015 Genetics
protein
change
teosinte glume architecture -
tga1
109. Makarevitch et al. 2015 PLoS Genetics
single TE family
many genes
new insertions activate expression
GRMZM2G071206
stress/control)
2
4
6
8
10
12
-2
0
2
4
6
8
10
12
14
Lines with the
TE insertion
Lines without the
TE insertion
GRMZM2G108149
A
B
Log2(stress/control)
on Septemhttp://biorxiv.org/Downloaded from
0.5
1.0
1.5
2.0
2.5
3.0
3.5
Oh43
B73
Mo17
(stress/control)
0%
20%
40%
60%
80%
100%
alaw
dagaf
etug
flip
gyma
ipiki
jeli
joemon
naiba
nihep
odoj
pebi
raider
riiryl
ubel
uwum
Zm00346
Zm02117
Zm03238
Zm05382
Salt
UV
Heat
Cold
B
A
Percentofconserved
genes
on September 9, 2014http://biorxiv.org/Downloaded from
*
**
***
*
*
single gene,
many individuals
112. Mu
KNOTTED1
kn1
Greene, et al., 1994
http://pmb.berkeley.edu/sites/default/files/users/Knotted1%20mutant.jpgDoebley 2004, Studer et al., 2011
tb1
Hopscotch
ZmCCT
CACTA
Yang et al., 2013