Chimeric types of chromosome X in bottom-fermenting yeasts |
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Authors: | T Ogata M Izumikawa H Tadami |
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Institution: | Brewing Research &Development Laboratory, Asahi Breweries, Ltd, Ibaraki, Japan |
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Abstract: | Aim: To determine the structure of the chimeric chromosome X of bottom-fermenting yeasts. Methods and Results: Eight cosmid clones carrying DNA from chromosome X of bottom-fermenting yeasts were selected by end-sequencing. Four of the cosmid clones had Saccharomyces cerevisiae (SC)-type and Saccharomyces bayanus (SB)-type chimeric ends, two had SC-type ends and two had SB-type ends. Sequencing revealed that the bottom-fermenting yeast strains in this study had four types of chromosome X: SC–SC, SC–SB, SB–SC and SB–SB. The translocation site in the chimeric chromosome is conserved among bottom-fermenting yeast strains, and was created by homologous recombination within a region of high sequence identity between the SC-type sequence and the SB-type sequence. Conclusions: Existing bottom-fermenting yeast strains share a common ancestor in which the chimeric chromosome X was generated. Significance and Impact of the Study: The knowledge gained in this study sheds light on the evolution of bottom-fermenting yeasts. |
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Keywords: | bottom-fermenting yeasts chimeric types of chromosome chromosome X hybrid yeast strain yeast phylogeny |
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