Isabelle Colas
Dr Isabelle Colas is a geneticist in the Cell and Molecular Sciences group.
Current research interests
During meiosis, homologous chromosome arms can exchange via the recombination mechanism essential for gene shuffling. It starts by the formation of Double-stranded breaks (DSBs), lesions in the arms of chromosomes which initiate gene conversion and crossing. The frequency and the distribution of the DSBs throughout the genome seem to correlate with the frequency and distribution of meiotic recombination events, but DSBs formations are not random, and seem to appear at very specific region of the genome. In wheat, rye and barley, genetic recombination frequency is high near the telomeres, but rare towards the centromeres while in Arabidopsis the recombination seems to be in the region of low chromatin condensation.
Breeding programmes have the objectives to develop more productive and more stable varieties. Hybridization and selection are frequently employed in plant breeding and the success of introgression of special traits such as disease resistance relies on genetic recombination between the host and alien chromosomes. However, because chiasmata are more frequent towards the telomeres, it implies that a large area of the chromosomes rarely recombines. Therefore, a better understanding of chromosome pairing, synapsis and recombination would enable in creating tools for manipulation of meiosis to improve cereal breeding.
I am especially interested in the cross talk between chromosome synapsis and recombination and their effect on chromatin remodelling. We are currently mapping and characterising a collection of 14 desynapctic mutants first described in early 70s (Hernandes-Soriano, 1973). We are also generating transgenics plant for specific genes of interest to elucidate the mechanism of crossing over control in barley in collaboration with various partner (MeioSys) from the meiosis field and the university of Dundee (A. Barakate, C. Halpin). I am also interested how the chromatin landscape might affect recombination hotspot in barley and within its ancestors (collaboration with A. Flavell).
Past research
After my university degrees I was determined to work on crop improvement for breeding and make a better food for the future. I started my career in a private company, AGROGENE S.A., specialised in providing molecular markers for breeding program and GMO testing for the worldwide seed market. Supervised by Dr P. Isaac, I was specialised in technical support for our sequencers/analyzer/robot (Applied Biosystems ABI310, 3100, 7700 &7900 and Qiagen robot Q3000) and developing new molecular biology protocols.
I then decided to increase my experience in crop science and started a PhD at the John Innes Centre with Pr G. Moore and P.J. Shaw on the wheat Ph1 locus topic. This is were I developed my main interest in meiosis and the use of cytogenetic techniques to elucidate gene mechanism. I also successfully developed a proteomic approach to study phosphorylation of wheat histone during meiosis and it's affect on chromatin remodelling one of my favourite topic.
Bibliography
- Colas, I.; Darrier, B.; Arrieta, M.; Mittmann, S.U.; Ramsay, L.; Sourdille, P.; Waugh, R., (2017) Observation of extensive chromosome axis remodeling during the "diffuse-phase" of meiosis in large genome cereals., Frontiers in Plant Science, 8, Article No. 1235.
- Colas, I.; Ramsay, L.; Waugh, R., (2017) Barley meiosis The importance of sticking together., Atlas of Science, 7 March 2017.
- Colas, I.; Baker, K.; Flavell, A.J., (2016) Cytology and microscopy: Immunolocalization of covalently modified histone marks on barley mitotic chromosomes., Bio-Protocol, 6, Article No. e1841.
- Colas, I.; Macaulay, M.; Higgins, J.D.; Phillips, D.; Barakate, A.; Posch, M.; Armstrong, S.J.; Franklin, F.C.H.; Halpin, C.; Waugh, R.; Ramsay, L., (2016) A spontaneous mutation in MutL-Homolog 3 (HvMLH3) affects synapsis and crossover resolution in the barley desynaptic mutant des10., New Phytologist, 212, 693-707.
- Phillips, D.; Jenkins, G.; Macaulay, M.; Nibau, C.; Wnetrzak, J.; Fallding, D.; Colas, I.; Oakey, H.; Waugh, R.; Ramsay, L., (2015) The effect of temperature on the male and female recombination landscape of barley., New Phytologist, 208, 421-429.
- Baker, K.; Dhillon, T.; Colas, I.; Cook, N.; Milne, I.; Milne, L.; Bayer, M.; Flavell, A.J., (2015) Chromatin state analysis of the barley epigenome reveals a higher-order structure defined by H3K27me1 and H3K27me3 abundance., Plant Journal, 84, 111-124.
- Baker, K.; Bayer, M.; Cook, N.; Dreizig, S.; Dhillon, T.; Russell, J.; Hedley, P.E.; Morris, J.; Ramsay, L.; Colas, I.; Waugh, R.; Steffenson, B.; Milne, I.; Stephen, G.; Marshall, D.; Flavell, A.J., (2014) The low recombining pericentromeric region of barley restricts gene diversity and evolution but not gene expression., The Plant Journal, 79, 981-992.
- Barakate, A.; Higgins, J.D.; Vivera, S.; Stephens, J.; Perry, R.M.; Ramsay, L.; Colas, I.; Oakey, H.; Waugh, R.; Franklin, F.C.H.; Armstrong, S.J.; Halpin, C., (2014) The synaptonemal complex protein ZYP1 is required for imposition of meiotic crossovers in barley., The Plant Cell, 26, 729-740.
- Ramsay, L.; Colas, I.; Waugh, R., (2014) Modulation of meiotic recombination., In: Kumlehn, J. & Stein, N. (eds.). Biotechnological Approaches to Barley Improvement, Part II. Springer, Berlin, Chapter 16, pp311-329.
- Greer, E.; Martin, A.C.; Pendle, A.; Colas, I.; Jones, A.M.E.; Moore, G.; Shaw, P., (2012) The Ph1 locus suppresses Cdk2-type activity during premeiosis and meiosis in wheat., The Plant Cell, 24, 152-162.
- Colas, I.; Koroleva, O.; Shaw, P.J., (2010) Mass spectrometry in plant proteomic analysis., Plant Biosystems 144, 703-714.
- Colas, I.; Shaw, P.; Prieto, P.; Wanous, M.; Spielmeyer, W.; Mago, R.; Moore, G., (2008) Effective chromosome pairing requires chromatin remodelling at the onset of meiosis., Proceedings of the National Academy of Sciences of the United States of America (PNAS),105, 6075-6080.
- Griffith, S.; Sharp, R.; Foote, T.N.; Bertin, I.; Wanous, M.; Reader, S.; Colas, I.; Moore, G., (2006) Molecular characterization of Ph1 as a major chromosome pairing locus in polyploid wheat., Nature, 39, 749-752.
Scientific posters/conferences
| Attachment | Size |
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 Control of Meiotic Recombination in Barley
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| Meiotic Recombination in Barley
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| The use of the barley desynaptic mutants to study recombination in cereals.pdf | 1.07 MB |
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