Uitnodiging doctoraatsverdediging Ilya Kirov

Titel: Physical mapping of genes on plant chromosomes

The defence will take place on Thursday, 09 February 2017, 17hr, at UZ Gent in Aud E (Blok B; entrance 32), De Pintelaan 185, 9000 Gent.
The defence will be followed by a reception to which you are kindly invited. Please confirm your attendance before February 1 to


Physical maps showing the real position of DNA sequences in the genome are a valuable tool for comparative genomics, study on genome organisation and gene isolation. Due to the genome complexity, development of a physical map by Fluorescence In Situ Hybridisation (FISH) visualization of genes on chromosomes is a very challenging task. Very sensitive methods, such as Tyramide-FISH, are required. The aim of this thesis was to optimize Tyramide-FISH for physical mapping of unique short DNA probes in plants. Allium, as a model plant, and Rosa, as a non-model plant, were used for this technology development, followed by its application for physical mapping of single-copy genes and physical map construction. A new protocol for chromosome preparation, named ‘SteamDrop’, was developed. The optimised Tyramide-FISH detection technique allowed to anchor three linkage groups to the physical chromosomes of Rosa wichurana. To further improve the Tyramide-FISH mapping procedure, multicolor and high-resolution Tyramide-FISH were established yielding a 10-20 times higher resolution for gene mapping. Using this approach, seven genes were successfully mapped on pachytene chromosomes 4 and 7 of Rosa wichurana and a detailed pachytene map was constructed for these chromosomes. In addition, FISH-based chromosome markers were designed for the chromosomes of Rosa and Allium. By combining these cytogenetic markers with chromosome morphology measurements, all 7 mitotic chromosomes of R. wichurana and all 8 chromosomes of A. fistulosum could be identified. The developed techniques allow easy visualization of genes as small as 1.1 Kb on plant chromosomes and circumvent technical issues that limited Tyramide-FISH applications previously. In the future, Tyramide-FISH will be valuable to accelerate and verify Rosa and Allium genome sequencing projects and will contribute to further progress in plant genome physical mapping and comparative genomics.