Abstract
Occasional hybridisation between closely related species is supposed to be a process that allows horizontal gene transfer and thus may have a significant impact on the evolution of species. The Saccharomyces sensu stricto group is an excellent experimental model system for studying the hybridisation process and its consequences because its species are in a stage of incomplete genetic isolation. Our recent results revealed that the alloploid Saccharomyces hybrid genome is unstable and undergoes a gradual stabilisation process leading to a smaller mosaic genome composed of elements of two or more species. Now we propose a research project to elucidate the mechanism(s) of alloploid genome stabilisation. We will analyse 'natural' (presumably stabilised) and laboratory-made 'artificial' (unstable) hybrids and their segregants by means of conventional genetic methods, molecular species-specific markers covering the entire genomes of the hybridising species, electrophoretic karyotyping, array-CGH, etc. The examination of the natural hybrids will possibly show the terminal types of the stabilisation process taking place in natural environment. The investigation of the mitotic and meiotic segregation of the laboratory hybrids will identify the major routes of genome reduction leading to stabile mosaic genome structures. Apart from the obvious basic aspects, the results may also have applied relevance since the Saccharomyces species are widely used in fermentation technologies.
Hungary