Analysis of mutations of Saccharomyces cerevisiae induced by ionizing radiation

• 1、The School of Radiation Medicine and Protection, Medical College of Soochow University, Suzhou Jiangsu 215123

Abstract：Objective: To establish a next-generation sequencing-based mutation analysis process and to reveal the number and distribution of mutations in Saccharomyces cerevisiae induced by ionizing radiation. Method: Wild-type and RAD52 gene knockout Saccharomyces cerevisiae were treated with 0 Gy, 50 Gy and 100 Gy X-rays. Radiosensitivity was evaluated by growth curve and colony formation experiments. Twenty clones of each group were further cultured, and then genomic DNA was extracted and subjected to paired-end 150 bp sequencing on the Illumina platform. The sequencing files were aligned to the reference genome, and then mutations were called using GATK analysis process. The mutations were verified using Sanger sequencing. The numbers, types, distributions, ratios and effects on encoded proteins were further analyzed. Results: Our data indicated that the mutations of RAD52 gene knockout Saccharomyces cerevisiae were more than that of wild-type. Administration of ionizing radiation increased the mutation rates. The proportions of transition were higher in the 100 Gy-treated groups. RAD52 gene knockout led to a higher frequency of GC to AT mutations.The 100 Gy-treated groups exhibited a higher frequency of mutations in noncoding regions, and the proportions of nonsynonymous mutations in single nucleotide variations were as expected. Conclusion: This study established a mutation analysis process for Saccharomyces cerevisiae and revealed the quantity and distribution patterns of ionizing radiation-induced mutations in wild-type and RAD52 gene knockout Saccharomyces cerevisiae.

Keywords： radiation medicine mutation Saccharomyces cerevisiae single nucleotide variant insertion/deletion mutation