Ehling U H, Neuhäuser-Klaus A
GSF-Institut für Säugetiergenetik, Neuherberg, F.R.G.
Mutat Res. 1991 Sep-Oct;250(1-2):447-56. doi: 10.1016/0027-5107(91)90201-x.
1-Methyl-1-nitrosourea (MNU) induced specific-locus mutations in mice in all spermatogenic stages except spermatozoa. After intraperitoneal injection of 70 mg/kg body weight of MNU a high yield of specific-locus mutations was observed in spermatids (21.8 x 10(-5) mutations per locus per gamete). The highest mutational yield was induced in differentiating spermatogonia. In 1594 offspring we observed 5 specific-locus mutants (44.8 x 10(-5) mutations per locus per gamete). In addition, 2 mosaics were recovered, which gave a combined mutation rate of 62.7 x 10(-5). In As spermatogonia the mutation rate was 3.9 x 10(-5). The same dose of 70 mg/kg of MNU induced dominant lethal mutations 5-48 days post treatment, mainly due to post-implantation loss in spermatids and spermatocytes. It is interesting to compare the induction pattern of mutations by MNU with methyl methanesulfonate (MMS), ethyl methanesulfonate (EMS) and ethylnitrosourea (ENU). Based on the different spermatogenic response of the induction of specific-locus mutations we can characterize the 4 mutagens in the following way: EMS = MMS not equal to MNU not equal to ENU.
1-甲基-1-亚硝基脲（MNU）可在除精子外的所有生精阶段诱导小鼠产生特定位点突变。腹腔注射70毫克/千克体重的MNU后，在精子细胞中观察到高频率的特定位点突变（每个位点每个配子有21.8×10⁻⁵个突变）。在分化中的精原细胞中诱导出的突变率最高。在1594只后代中，我们观察到5个特定位点突变体（每个位点每个配子有44.8×10⁻⁵个突变）。此外，还发现了2个嵌合体，其综合突变率为62.7×10⁻⁵。在A型精原细胞中，突变率为3.9×10⁻⁵。相同剂量70毫克/千克的MNU在处理后5至48天诱导显性致死突变，主要是由于精子细胞和精母细胞着床后死亡。将MNU与甲磺酸甲酯（MMS）、乙磺酸乙酯（EMS）和乙基亚硝基脲（ENU）诱导突变的模式进行比较很有意思。根据诱导特定位点突变的不同生精反应，我们可以用以下方式对这4种诱变剂进行表征：EMS = MMS ≠ MNU ≠ ENU。
