Gudi R, Sandhu S S, Athwal R S
Department of Microbiology and Molecular Genetics, New Jersey Medical School, Newark 07103.
Mutat Res. 1990 Oct;234(5):263-8. doi: 10.1016/0165-1161(90)90038-p.
An in vivo micronucleus assay using mouse bone marrow for identifying the ability of chemicals to induce aneuploidy and/or chromosome breaks is described. Micronucleus formation in bone-marrow erythrocytes of mice is commonly used as an index for evaluating the clastogenicity of environmental agents. However, micronuclei may also originate from intact lagging chromosomes resulting from the effect of aneuploidy-inducing agents. We have used immunofluorescent staining using anti-kinetochore antibodies to classify micronuclei for the presence or absence of kinetochores. Micronuclei positive for kinetochores are assumed to contain intact chromosomes and result from induced aneuploidy; while those negative for kinetochores contain acentric chromosomal fragments and originate from clastogenic events. The assay was evaluated using X-irradiation (a known clastogen) and vincristine sulfate (an aneuploidy-inducing agent). A dose-related response for the induction of micronuclei was observed for both agents. Micronuclei induced by X-irradiation were negative for kinetochores while the majority of the micronuclei resulting from vincristine treatment contained kinetochores. Thus, the micronucleus assay in combination with immunofluorescent staining for kinetochores may provide a useful method to simultaneously assess the ability of chemicals to induce aneuploidy and/or chromosome breaks.
本文描述了一种利用小鼠骨髓进行的体内微核试验，用于鉴定化学物质诱导非整倍体和/或染色体断裂的能力。小鼠骨髓红细胞中的微核形成通常用作评估环境因子致断裂性的指标。然而，微核也可能源自非整倍体诱导剂作用导致的完整落后染色体。我们使用抗动粒抗体的免疫荧光染色对微核进行分类，以确定是否存在动粒。动粒阳性的微核被认为含有完整染色体，是由诱导的非整倍体产生的；而动粒阴性的微核则含有无着丝粒染色体片段，源自致断裂事件。使用X射线照射（一种已知的致断裂剂）和硫酸长春新碱（一种非整倍体诱导剂）对该试验进行了评估。两种试剂均观察到微核诱导的剂量相关反应。X射线照射诱导的微核动粒呈阴性，而长春新碱处理产生的大多数微核含有动粒。因此，微核试验结合动粒的免疫荧光染色可能提供一种有用的方法，用于同时评估化学物质诱导非整倍体和/或染色体断裂的能力。
