Ethyl methanesulfonate EMS

For a number of decades, the method of choice to obtain B. subtilis mutant libraries is the treatment of an exponentially growing culture with a mutagen, frequently ethyl methanesulfonate (EMS) or nitrosomethylguanidine (NTG). 

Treatment for two complete cell cycles with increasing SAB concentrations significantly elevated the SCE frequency in CHO cells (Fig. 2a). Exposure to the alkylating agents MMS (10" M), ethyl nitrosourea (ENU, 10" Af), ethyl methanesulfonate (EMS, 10"" M), or N-methyl-N -nitro-N-nitrosoguanidine (MNNG, 10" M), in combination with SAB resulted in synergistic increases in SCEs (Fig. 2b). 

Irradiation and Alkylation Conditions. X-ray doses of 3-6 Gy were delivered from a Phillip s RTIOO X-ray machine (200 kVp 15 mA with a nominal half value layer of 0.35 cm copper). Cultures were inadiated with an incident dose rate of 1.3 J m s UV light (254 nm). Cultures were exposed to various concentrations of N-methyl-N -nitro-N-nitrosoguanidine (MNNG) (Aldrich Chemical Co., Milwaukee, Wl), MMS (ICN Pharmaceuticals, Hainview, NY), ethyl methanesulfonate(EMS) (ICN Pharmaceuticals), or ethyl nitrosourea (ENU) (a gift of B. Singer, University of California, Berkeley), in tissue culture medium for 60 min to 4 h. 

Finally, studies in the UV-sensitive XP cells also showed a divergence between SCE and chromosome aberrations. XP is abnormally sensitive to induction of chromosome aberrations by certain chemicals such as 4-nitroquinoline-1-oxide (4-NQO), whereas other chemicals such as A -methyl--nitro-A -nitrosoguanidine (MNNG) and ethyl methanesulfonate (EMS) produce the same amount of chromosome aberration in XP and normal cells. Wolff et showed that XP cells are consistently more sensitive than... 

Recently, Tazima and associates compared chemically induced mutations with those induced by radiation for embryonic lethality. In this experiment, mutations were induced as mosaics by treating oocytes with ethyl methanesulfonate (EMS) or diethylsulfate (DES) and led to homozygotes in order to examine embryonic lethality. The data are given in Table 1, together with those previously obtained by irradiating the corresponding stages of oocytes. 

Traditional genetics involves the induction of mutations in populations through mutagenesis and screening for mutants with desirable phenotypes. The most commonly used mutagenesis methods, such as ethyl methanesulfonate (EMS) and transfer (T)-DNA, have been highly successful in Arabidopsis genetics,... 

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