MOLECULAR GENETIC STUDIES ON THE DYNAMIC GENOME OF YEAST IN RESPONSE TO ENVIRONMENTAL STRESSES

Abstract

Dilution plating was used to compare number of colonies means for five yeast strainsas control and heat or salt stresses. S1 strain was sensitive when exposed to 20°C, whileit was more tolerant at 40°C, 0.5 M and 1 M of NaCl.S2 strain showed significant difference when exposed to temperature at 20°C, 40°C and 1 M NaCl, while it was tolerant in 0.5 M of NaCl. S3 and S4 strains showed more tolerance at heat and salt stresses. S5 strain wasn't affected when exposed to 20°C and 40°C, while the difference was significant when exposed to 0.5 M and 1 M on NaCl.TheSDS-PAGE electrophoretic patterns showed 15 bands. They were different in patterns of all genotypes expect S2 and S4 strains have the same banding pattern between control and 20oC. Five random primers were used to identify and characterize betweencontrol and treatments for yeast strains by RAPD-PCR analysis. A total of DNA fragments ranged in size from 3042 to 81 base pair were recorded with polymorphic and monomorphic pattern. The RAPD molecular marker confirmed a presence of difference between the control and stressed yeast strains