Laboratory of Molecular Cytogenetics and Cytometry
Institute of Experimental Botany AS CR

Polyploidy is a key force in the evolution of flowering plants. Allopolyploidy involves a merge of distanc genomes followed by whole-genome duplication. Recently formed allopolyploids retain duplicated copies of most genes on homoeologous chromosomes. However, it appears that the contribution of parentel genomes need not to be equal and that altered gene expression is common. Such a divergence is believed to develop in two phases. The first takes place immediately after the hybrid formation, the second is a gradual evolution of gene expression mediated by diversification of duplicated genes. Here we propose to sequence transcriptome of two grass species (Festuca pratensis and Lolium multiflorum). The sequences will be used to design a Nimblegene chip, which will be used to analyze gene expression in three successive generations of newly synthesized Festuca × Lolium hybrids. This will provide novel data on genome interactions and silencing of genes belonging to the parental genomes. Moreover, komparative genomic hybridization will be used to identify the loss of particular gene loci as a consequence of the merge of two distinct genomes.

The large size and polyploid nature of the nuclear genome of bread wheat pose a great challenge for the understanding of complete genome information, genome sequencing and gene discovery. This task could be simplified by fractionating the genome into small and defined parts. Here we propose to create two subgenomic BAC libraries specific for short and long arm of wheat chromosome 3D. Their creation will mark the completion of BAC resources for homeologous group 3, which has been selected for the pilot phase of the wheat genome sequencing project. 3D-specifc BAC resources developed in this project will be used to develop a molecular cytogenetic map and, in collaboration with Prof. J. Dvooák (UC, Davis), a physical contig map of 3D. They will also be used for targeted isolation of low-copy (potentially coding) DNA sequences, discovery of gene-rich regions on 3D, and for high-throughput mapping of expressed sequences to chromosome 3D using wheat GeneChip (collaboration with Prof. T. Close, UC, Davis). The se advances will open avenues for comparative analysis of the wheat genome evolution and the analysis of interaction between the genomes of allopolyploid species. The results obtained and genomic resources generated, will allow the isolation and manipulation of important genes to improve tolerance of wheat to biotic and abiotic stresses and quality of plant products.