Department of Biology, Institute of Biosciences, UNESP - Univ Estadual Paulista, Av. 24-A, 1515, 13506-900, Rio Claro, SP, Brazil,
Environ Sci Pollut Res Int. 2015 Jul;22(13):9796-806. doi: 10.1007/s11356-015-4134-2. Epub 2015 Feb 3.
Nucleolar alterations resulting from the action of either chemical or physical agents can serve as important genotoxicity biomarkers. In this study, the efficiency of AgNOR banding technique to identify the presence of nucleoli in micronucleus and assess nucleolar alterations in aberrant cells of Allium cepa was evaluated. Seeds of this plant were exposed to both water samples from a river that receives untreated urban effluent and to the trifluralin herbicide (0.84 mg/L concentration), both analyzed in two different seasons (summer and winter seasons). Samples induced significant frequencies of chromosomal and nuclear aberrations and micronuclei, as observed in cells submitted to conventional chromosomal staining. The herbicide caused a significant increase in the number of nucleoli and micronuclei, interpreted as due to the elimination of excessive nucleolar material resulting from polyploidization. The use of the AgNOR technique enabled the identification of both the presence of the nucleolus in some micronuclei and the nucleolar organizer region (NOR) behavior of aberrant cells. The NOR-banding technique showed to be an efficient tool for studying the genotoxic effects caused by a xenobiotics and a complex environmental sample.
核仁改变是由于化学或物理因素作用的结果，可以作为重要的遗传毒性生物标志物。在这项研究中，评价了银染核仁组成区（AgNOR）带技术在鉴定微核中核仁存在和评估异常细胞核仁改变方面的效率。将该植物的种子暴露于接收未经处理城市污水的河流的水样和氟乐灵除草剂（0.84mg/L 浓度）中，在两个不同季节（夏季和冬季）进行分析。如常规染色体染色观察到的那样，这些样品诱导了染色体和核异常以及微核的显著频率增加。除草剂导致核仁数量和微核显著增加，这被解释为多倍体化导致多余核仁物质的消除。AgNOR 技术的使用能够识别某些微核中核仁的存在以及异常细胞的核仁组织区（NOR）行为。NOR 带技术被证明是研究外源性化学物质和复杂环境样品引起的遗传毒性作用的有效工具。
