|
Heslop-Harrison Group Homepage Science Bovid (cow) diversity People Methods/techniques In situ Hybridization Molecular methods- lab protocols Technology development Courses and Science Pictures Journal editing Policy Information/Publications Jack Heslop-Harrison Links Site information
|
ConferencesFuture Conferences 1. European PARADIGM Meeting, Guadeloupe , France 1-5 April 2005 http://paradigm.cirad.fr/index.html 2. European Cytogenetics Association V European Cytogenetics Conference Madrid ( Spain ), 5-7 June, 2005 http://eca2005madrid.com 4. XVII Int Botanical Congress Vienna 17-22 July 2005 5. Geometry of the Genome, Leicester The Departments of Mathematics, Genetics and Biology, University of Leicester together with IHES (The Institut des Hautes Études Scientifiques in Bures-sur-Yvette, France), group of Prof. M Gromov are or gani zing the Workshop "Geometry of Genome: visualization of structures, hidden in genomic sequences" 22-24 September, 2005. For further details please contact Professor Alexander Gorban Email: ag153@leicester.ac.uk 6. Biotechnology Havana 2005: For a sustainable food production November 27th to December 2nd, 2005, Havana , Cuba Courses For details of requirements for an in situ hybridization course, see the methods section of this website. Pat Heslop-Harrison is convenor for the course “Domestication of Plants and Animals: Past, Present and Future”. Further details are under teaching He is also involved with teaching in collaborations in Malaysia under the British Council FICHE project with Professor Yasmin Othman, and with the EU Erasmus project in Portugal .
European Cytogenetics Conference, Paris July 2001 [Heslop-Harrison is Organizer of the Workshop Plant Cytogenetics. Confirmed or invited speakers include Viegas, von Bothmer, Puertas, D'Hont, Vyskot, Jahier, Anamthawat-Jonsson] Genome Evolution and Sources of Diversity in Crop Plants Repetitive DNA
sequences make up 50-90% of the genome of most higher plant species and
are rapidly evolving: individual motifs show changes in both copy number
and sequence between closely related species. In contrast, genes are similar
even over large taxonomic distances, evidenced by the fact that they can
often be found in different species by amplification with conserved primers
for PCR. Study of repetitive DNA in the context of genomic diversity and
plant evolution is very important because of the sheer amount, its rapid
evolution and the demonstrated effect on gene duplication and regulation
of expression – key contributors to biodiversity. Some variability in
chromosome evolution is associated with genome expansion and increase
in copy number of repeats, but there are also (largely unknown) mechanisms
for genome size reduction: Arabidopsis thaliana, with a small genome
size, arose from Crucifer species where genomes were almost certainly
much larger. The variability in repeat sequences also allows assessment
of diversity within and between species, giving information about the
generation of new diversity as well as assessment of loss. Studies of plant nuclear organization have lead to identification
and characterization of the many processes in genome evolution, from molecular
events to chromosomal evolution, alien chromosome integration and polyploidy,
and show the impressive plasticity of the genome and the rapid amplification
and fixation of novelties, many events occurring in steps rather than
as clock-like changes. In this presentation, I will address the
contribution of repetitive DNA sequences to chromosomal evolution and
demonstrate the application of tools of molecular cytogenetics to understanding
chromosomal evolution within species and in speciation. Further information available from www.molcyt.com or www.heslop-harrison.com Relevant citations:Heslop-Harrison JS. 2000. Comparative genome organization in plants: from sequence
and markers to chromatin and chromosomes. Plant Cell 12:
617-635. Schwarzacher T, Heslop-Harrison JS. 2000. Practical in situ hybridization. Oxford: Bios. 203+xii pp. European Science Foundation Retrotransposons, Marsailles May 2001 Retroelement
diversity in the Gymnosperms analysed by microarray and sequencing methods J.S.
Heslop-Harrison, Trude Schwarzacher and Nikolai Friesen Department
of Biology, University of Leicester, LE1 7RH UK E-mail:
PHH4@le.ac.uk; Website: www.heslop-harrison.com Pine and spruce trees have very large genomes (eight times human or 50% larger than wheat), but are diploid with 2n=24 chromosomes. We have analysed the sequence diversity and abundance of retroelements of the copia, gypsy, LINE and pararetroviral groups in a wide range of gymnosperms from the Northern and Southern hemisphere. Retroelements are a major genomic component in these species, as in angiosperm plants and the animal kingdom, and retroelement-related sequences represent about 50% of the genome. Different families have individual and characteristic genomic distributions along the chromosomes of each species. To measure the relative abundance of different retroelements in the species groups, and characterize the structure and distribution of different families, we have used three-colour microarray hybridization with cloned elements as the target DNA on the slide surface and probing with genomic DNA from different gymnosperms. Rapid and quantitative analysis of both element and species diversity and evolutionary patterns was possible. Most retroelement families were distributed widely among the gymnosperms although differing in abundance. When gymnosperm sequences were analysed together with retroelements from other species, the monophyletic origin of plant copia, gypsy and LINE groups was well supported, with an additional clade including badnaviral plant sequences as well as animal and fungal gypsy elements. No primary branches divided major taxonomic clades such as angiosperms, monocotyledons or gymnosperms suggesting that much of the existing diversity was present early in plant evolution. The results put the evolution of the large and relatively conserved genome structure of gymnosperms into the context of the diversity of other groups of plants. Perth September 2002 12th Australasian Plant Breeding Conference Exploiting novel germplasm Less than 0.1% of the world’s plant species are grown as crops, and even within these crop species, only a small proportion of the total genetic variability is used in commercial varieties. Here, six inter-related questions about why it might be desirable to exploit novel germplasm in breeding programmes are addressed: to exploit plant diversity, to meet continuing breeding objectives in major crops, to develop new crops, to meet new needs from existing crops, to ensure all the world’s people benefit from breeding programmes, and to ensure the sustainability of crop production. Both species which are rarely cultivated, and genes from accessions and species related to existing crops, can be exploited to meet the need for improvement of agricultural production. Molecular and statistical methods have the potential to speed introduction of novel germplasm: allowing quantitative assessment of diversity, characterization of desirable genes, tracking of chromosomes, genes or gene combinations through breeding programmes, selection of rare recombination events and direct gene transfer through transformation. But the challenges of maintaining desirable characters in varieties incorporating novel germplasm, overcoming genetic stability problems, and ensuring safety are considerable.
|
