TY - JOUR
T1 - Induction of micronuclei in maize root‐tip cells and a correlation with forward mutation at the yg2 locus
AU - Wagner, Elizabeth D.
AU - Plewa, Michael J.
PY - 1985
Y1 - 1985
N2 - A standard protocol for a micronucleus assay in root tips of Zea mays was developed and calibrated using 137Cs gamma radiation, ethylmethanesulfonate (EMS), and N‐ethyl‐N‐nitrosourea (ENU). The root tips were sampled 1, 3, and 5 days after the treatment period. Primary root tips (sampled 1 day after treatment) were the most responsive with the highest frequencies of micronuclei. The frequencies then decreased to control values after 3 days. By treating the same kernels for this assay and the yellow‐green‐2 (yg2) forward mutation assay, it was possible to analyze and compare the induction kinetics of micronuclei formation in root‐tip cells and forward mutation at the yg2 locus in leaf primordial cells. Forward mutation at the yg2 locus by gamma rays, EMS, or ENU exhibited one hit kinetics. The induction of micronuclei demonstrated nonlinear kinetics with a significant increase over controls above 200 rads gamma rays, 10 mM EMS, or 250 μM ENU. ENU induced a higher frequency of micronuclei at all treatment concentrations than did gamma radiation or EMS. The data suggest that a higher relative proportion of yg2 mutant sectors induced by ENU may be due to chromosome aberrations than those induced by gamma radiation or EMS.
AB - A standard protocol for a micronucleus assay in root tips of Zea mays was developed and calibrated using 137Cs gamma radiation, ethylmethanesulfonate (EMS), and N‐ethyl‐N‐nitrosourea (ENU). The root tips were sampled 1, 3, and 5 days after the treatment period. Primary root tips (sampled 1 day after treatment) were the most responsive with the highest frequencies of micronuclei. The frequencies then decreased to control values after 3 days. By treating the same kernels for this assay and the yellow‐green‐2 (yg2) forward mutation assay, it was possible to analyze and compare the induction kinetics of micronuclei formation in root‐tip cells and forward mutation at the yg2 locus in leaf primordial cells. Forward mutation at the yg2 locus by gamma rays, EMS, or ENU exhibited one hit kinetics. The induction of micronuclei demonstrated nonlinear kinetics with a significant increase over controls above 200 rads gamma rays, 10 mM EMS, or 250 μM ENU. ENU induced a higher frequency of micronuclei at all treatment concentrations than did gamma radiation or EMS. The data suggest that a higher relative proportion of yg2 mutant sectors induced by ENU may be due to chromosome aberrations than those induced by gamma radiation or EMS.
KW - ethylmethanesulfonate
KW - ethylnitrosourea
KW - gamma rays
KW - maize
KW - micronuclei
KW - yg2
UR - http://www.scopus.com/inward/record.url?scp=0022397131&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0022397131&partnerID=8YFLogxK
U2 - 10.1002/em.2860070604
DO - 10.1002/em.2860070604
M3 - Article
C2 - 4065059
AN - SCOPUS:0022397131
SN - 0192-2521
VL - 7
SP - 821
EP - 832
JO - Environmental Mutagenesis
JF - Environmental Mutagenesis
IS - 6
ER -