Nuclear Blebs Assay for Genome Instability in <i>Phaseolus vulgaris</i> L.

Abstract

Summary Micronuclei are extra nuclear structures, formed by the exclusion of chromosomes during cell division. The genotoxicity of a compound and its impact on the genome can be assessed via micronuclei formation. The present study has been undertaken to evaluate the mutagenic effect of the alkylating agent EMS on the meiotic behavior of pollen mother cells of Phaseolus vulgaris L. The cytological analysis revealed the induction of micronuclei at all the three administered concentrations of EMS, viz. 0.1, 0.3 and 0.5%. Besides micronuclei formation, other meiotic abnormalities associated with chromosomal segregation, such as stickiness, laggard, bridge, multivalent, etc., were also reported at metaphase I/II and anaphase I/II. The micronuclei formed would have two fates either it remains until the tetrad stage or is expelled out in the form of microcytes which will give rise to sterile pollen grains affecting the pollen fertility. The present study also documents the first instance of nuclear budding in Phaseolus vulgaris L. It is contemplated that these nuclear buds will later on convert into micronuclei. The micronuclei formation results in partial elimination of the genome, which could be efficiently utilized in breeding programmes for the production of addition and substitution lines. Similarly, haploid lines could also be produced by the complete loss of genome. It is therefore essential to understand the biological aspects of micronuclei formation, its consequences on the cell carrying it and other factors related to it so that in the future, it could be used as a marker of genetic damage and also be utilized in breeding programmes.

Laurus nobilis L.: assessment of the cytotoxic and genotoxic potential of aqueous extracts by micronucleus and Allium cepa assays

“…In the current study, the aqueous extract at the two concentrations significantly reduced the number of buds and caused alterations in nucleoli, including in relation to the negative control group. These changes are characteristic of agents with genotoxic potential, such as the positive control used in this study (Montanaro, Treré, Derenzini, 2008;Fenech et al, 2011;Kumar, Chaudhary, 2015). The reduction of these alterations in the cells treated with the extract indicates that it has a protective effect.…”

Evaluation of the cytotoxic and genotoxic potentials of the solubilized extract of the coffee waste using Allium cepa as a test system

“…In addition, the T5 treatment also showed a significantly higher number of cells whit nucleolar changes compared to the negative and positive controls ( Figure 3B and 3D), whereas the T3 treatment showed a significant number of cells with notched nucleus ( Figure 3F). These alterations are characteristic of cells that have been exposed to genotoxic agents, such as the positive control used in this work (MONTANARO et al, 2008;FENECH et al, 2011;KUMAR et al, 2015).…”

Nuclear Polymorphism Induced Genomic Instability in Cluster Bean [<i>Cyamopsis tetragonoloba</i> (L.) Taub.] (Fabaceae)

“…EMS is a monofunctional alkylating agent and is considered as a potent mutagen and carcinogen (Meuth and Arrand 1982). It has been documented in several previous findings that higher doses of gamma radiation (Verma and Khan 2016) and EMS (Kumar and Chaudhary 2015) lead to MN induction. The mutation frequency may either increase or decrease when physical and chemical mutagens act independently of each other or compete for the same sites (Srivastav and Raina 1981).…”