Effect of temperature on the male and female

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Effect of temperature on the male and female
Effect of temperature on the male and female
recombination landscape of barley
Luke Ramsay
2015 Monogram Network Meeting, Rothamsted Research 29th April – 1st May 2015
Effect of temperature on the male and female
recombination landscape of barley
Dylan Phillips1*, Glyn Jenkins1*, Malcolm Macaulay2, Candida Nibau1, Joanna Wnetrzak1,
Derek Fallding1, Isabelle Colas2, Helena Oakey3, Robbie Waugh2,4, Luke Ramsay2
1Institute of
Biological, Environmental and Rural Sciences (IBERS), Aberystwyth University, SY23 3DA, UK; 2The James Hutton Institute
(JHI), Cell and Molecular Sciences, Invergowrie, Dundee, DD2 5DA, UK; 3The James Hutton Institute (JHI), Information and
Computational Sciences, Invergowrie, Dundee, DD2 5DA, UK; 4Division of Plant Sciences, University of Dundee at The James Hutton
Institute, Invergowrie, Dundee, DD2 5DA, UK
2015 Monogram Network Meeting, Rothamsted Research 29th April – 1st May 2015
Overview
Recombination in barley
Meiosis & Recombination
Temperature effects on
recombination
Implication for control of
recombination
Patterns of recombination
Patterns of recombination
Skewed distribution of recombination vs gene content
This phenotype is common in Triticeae: Pooideae
Tight genetic control of Meiotic process
Effect on Patterns of Diversity
K. Baker et al Plant J 2014
Reduction in diversity and selection
in H. v. spontaneum
Limited haplotype variation in UK
elite barleys
Phenotype under genetic control
Jones, 1967
Selfing outbred spp. can result in lines with a loss of control of chiasmata distribution
Meiosis: specialized cell division
2n/4c
2n/4c
Meiosis I
Reduction division
2n/4c
2n/4c
2n/4c
2n/4c
Pachytene
Diplotene
Zygotene
Diakinesis
Prophase I
Leptotene
Chromosome pairing and Recombination
Metaphase I
Anaphase I
2n/4c
Telophase II
1n/1c
n=ploidy
c=chromatid
Anaphase II
1n/2c
Metaphase II
1n/2c
Prophase II
1n/2c
Telophase I
1n/2c
Meiosis II
Equational Division
4x
Gametes
WT
Meiotic progression
in barley
Leptotene
Leptotene/Zygotene
Zygotene
Pachytene
ASY1 ZYP1
ASY1 ZYP1
ASY1 ZYP1
ASY1 ZYP1
Metaphase II
ASY1 DAPI
Anaphase I
ASY1 DAPI
Metaphase I
ASY1 DAPI
Axis protein ASY1 (ASYNAPSIS1) Synapsis ZYP1 (ZIPPER1)
OMX 3D Structure Illumination Microscopy (3D-SIM) University of Dundee
Diplotene
ASY1 ZYP1
Crossover pathways
Leptotene
Zygotene
Pachytene
Diplotene
(Padillo et al., 2014)
Effect of temperature: wheat
Bayliss & Riley 1973
Evidence in older literature of the effect of temperature on recombination
(Restoration of wt chiasmata levels in nullisomic 5D tetrasomic 5A line)
Effect of temperature: barley
Higgins et al 2012
Barley plants (cv Morex) given heat stress (30˚C) show more interstitial chiasmata
in Metaphase I spreads … but fewer grains
Reciprocal backcrosses
Steptoe x Morex
Morex
♂
x
F1
Bc1 (MF)
x
Morex
Bc1 (FM)
♀
Crosses between two inbred six-rowed varieties ‘Steptoe’ & ‘Morex’
Crosses made with F1 grown at 15°C, 25°C & 30°C
Six Bc1 populations – reciprocal and temperature differences
96 Bc1 progeny genotyped with 384 BeadXpress Veracode SNP assay
Heterochiasmy
Male
Female
Ratio
15°C
987.1 cM
956.2 cM
1.05
25°C
1115.5 cM
920.3 cM
1.20
30°C
1359.3 cM
869.0 cM
1.58
Standard consensus map of regions covered = 969.2 cM (1090 cM)
Increase in total map length with increasing temperature on male side
Overall
Significant male: female difference
Significant interaction with temperature
Bc1 map comparisons
Comparison with physical map
Interstitial peri-centromeric region 9 cM – 57 cM ~400Mb
Bivalent length increase
a
b
c
2µm
(a) Immunolocalisation of ZYP1 in an embedded pachytene nucleus, positions of centromeres (red)
and 5S (green) are shown. (b) 2H and (c) 3H bivalent isolated from nucleus shown in (a).
Synaptonemal complex (SC) of bivalents 2H and 3H in male meiosis labelled with ZYP1
Pachytene nuclei embedded in polyacrylamide
Increase in length by 30% in response to an increase in temperature 15°C - 25°C
Known correlation of SC length and crossover frequency
MLH3 foci mark crossover positions (Class I)
(a) Immunolocalisation of ZYP1 (grey) and HvMLH3 (green) in an embedded pachytene nucleus.
(b) A single bivalent (grey) with the position of the HvMLH3 foci (green foci, arrowed).
MLH3 involved in resolution of double strand breaks into crossovers
– MLH3 foci mark Class 1 CO
At 15°C mean no. of MLH3 foci per nucleus is 20.2 (± 3.52)
which matches expectation of 21.8 crossovers from consensus barley map
Implies that ratio of class I to class II CO is higher in barley than Arabidopsis
MLH3 foci mark crossover positions (Class I)
(a) Immunolocalisation of ZYP1 (grey) and HvMLH3 (green) in an embedded pachytene nucleus.
(b) A single bivalent (grey) with the position of the HvMLH3 foci (green foci, arrowed).
At 15°C mean no. of MLH3 foci per nucleus is 20.2 (± 3.52)
The distribution changes to become more interstitial at 25°C
But the number at 25°C does not change significantly (18.6 ± 6.24)
Increase in 2H genetic map length (139 – 178 cM) due to more class II CO ??
Change in Distribution: Cell Cycle
Higgins et al 2012
During prophase I, nuclei expand at transitional stages and then contract and
meiotic events are in phase with this chromatin cycle
Initial distal meiotic events are synchronized with nuclei expansion periods,
whereas the interstitial events occur during periods of nuclei contraction
At 30°C S phase was 4 hours shorter and the initial axis formation and loading of
recombination proteins was more even
Stress induced heterochiasmy: Male/female asynchrony
Evidence from older literature
that temperature stress induces
asynchrony between progression
of male and female meioses.
Indicated that entry into meiosis
was faster on male side
-consistent with greater
recombination in male meiosis
and potentially with the shorter S
phase in stressed barley plants
(Higgins et al., 2012)
Bennett & Finch 1971
Bennett et al., 1973
Conclusions
Recombination in barley responds to environmental stress
– changes in crossover distribution
Distribution relates to cell cycle and timing of early meiotic events
Relationship between stress response and differences between male and
female meioses
– points to a common mechanism for recombination control in Triticeae
Potential application to access some genes in the peri-centromeric regions
Acknowledgements
The James Hutton Institute
Isabelle Colas
Robbie Waugh
Malcolm Macaulay
Sybille Mittmann
Mikel Arrieta
University of Aberystwyth
Dylan Phillips
Glyn Jenkins
Candida Nibau
Joana Wnetrzak
David Fallding
University of Dundee
Claire Halpin
Abdellah Barakate
Markus Posh (OMX)
University of Birmingham
Chris Franklin
Sue Armstrong
James Higgins
Ruth Perry
The research leading to these results has received funding from
the European Community's Seventh Framework Programme
FP7/2007-2013 under grant agreement n° 222883.

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