THE ANALYSIS OF THE RESTRICTION SITE POLYMORPHISM IN THE REPEATED SEQUENCES (RDNA, SUBTELOMERIC Y’ SEQUENCES AND RETROTRANSPOSON TLY) IN THE GENOMIC DNA OF THE INDUSTRIALLY USED SACCHAROMYCES CEREVISIAE STRAINS

Fatih IZGÜ*,o, Demet ALTINBAY*

*METU, Dept of Biology, Faculty of Science and Arts, Ankara, TURKEY.
oCorresponding Author

Summary:
S. cerevisiae BSP-1, BSP-2, BSP-3 and BSP-4 are industrially used baking strains that have same phenotypes, but claimed to be different strains by the industry due to variations in their fermentation activities in dough. In the present study, we have analyzed the rDNA sequences, subtelomeric Y’ sequences and retrotransposon Tyl that are highly repeated in the genomic DNA of the yeast S. cerevisiae. As these three types of repeats have different sequence arrangements in different strains of S. cerevisiae, the genomic DNA of the industrially used strains utilized in this study were subject to a series of cleavage reactions by five different restriction endonucleases (Eco RI, Hind III , Bam HI, Bgl II, Xho I) to interpret the sequence arrangements in each strain.
The rDNA sequence in each strain showed no restriction site polymorphism for the enzymes Eco RI, Hind III and Bgl II. The retrotransposon Ty1, when cut by Xho I, generated a same size fragment in all strains and the Y’ subtelomeric sequences also did not indicate any different arrangement when digested with Hind III, Bam HI, and Xho I.
The data obtained from this genomic analysis did not support the claims that these strains were different due to variations in fermentation activities in dough, although they have same phenotypes.

Key words:
S. cerevisiae, rDNA, Subtelomeric Y’ sequence, Retrotransposon Ty1, Restriction site polymorphism.