Rozdělení velkých genomů čeledi Triticeae tříděných chromozomů

Nuclear genomes of some Triticeae species are characterized by large size and prevalence of repetitive DNA sequences. These features hamper their physical mapping and gene cloning. Purification of individual chromosomes by flow cytometry can simplify these tasks by providing small and defined genome fractions. This lecture reviews the development of the methodology and its potential for genome mapping in barley, rye and wheat Due to small differences in relative DNA content, only one chromosome type can be discriminated and sorted in each of the three species. Cytogenetic stocks facilitate separation of other parts of the genomes as individual chromosomes, translocation chromosomes and chromosome arms. Chromosome analysis by flow cytometry permits quantitative detection of structural and numerical chromosome changes. Chromosomes sorted onto microscopic slides have been used for discovery of rare structural changes and for high-resolution cytogenetic mapping using FISH. The use of sorted chromosomes for HAPPY mapping, targeted isolation of low copy "genie" sequences, and high-throughput physical mapping of ESTs on microarrays are attractive options. As millions of chromosomes with intact DNA may be sorted, construction of BAC libraries is possible. Subgenomic, chromosome-specific and chromosome arm-specific BAC libraries have already been produced in wheat and represent unique resources for genomics of cereals