Micronucleus

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micronucleus

[¦mī·krō′nü·klē·əs]
(invertebrate zoology)
The smaller, reproductive nucleus in multinucleate protozoans.

Micronucleus

 

in infusorians, the smaller (generative) nucleus. The micronucleus is usually diploid and divides by mitosis; however, during the sexual process in infusorians (conjugation), it divides meiotically and gives rise to sexual nuclei or pronuclei. During the vegetative period, the genetic apparatus of the micronucleus remains inactive, does not synthesize ribonucleic acid, and has no influence on the phenotype of the organism.

References in periodicals archive ?
The prevalence of school children that had epithelial micronuclei in their stained buccal smears is 20.
What they found was that micronuclei frequency rose with increasing arsenic levels in rice.
Effect of laboratory protocol, scoring criteria, and host factors on the frequency of micronuclei.
In our study, it was observed that the increase in micronuclei after therapy, was not statistically significant which is explained by the fact that the amount of radiation induced to cells may be minimal.
Biomonitoring of four European populations occupationally exposed to pesticides: use of micronuclei as biomarkers.
The effect of morphine on micronuclei induction by mitomycin C.
Pastor S, Creus A, Parron T, Cebulska-Wasilewska A, Siffel C, Piperakis S and R Marcos Biomonitoring of four European populations occupationally exposed to pesticides: use of micronuclei as biomarkers.
0 software is the release of the Micronuclei Application Module that allows users to find, evaluate and quantitate micronuclei in nucleated cells for HCS.
The application of poectral karyotuping (SKY) an fluorescent in situ hybridization (FISH) technology to determine the chromosomal content(s) of micronuclei.
The tests confirmed the oral LD50 is greater than 2000 mg/kg, there was no oral toxicity in rats receiving 1000 mg/kg/day for 4 weeks, is not mutagenic to the bacteria used, did not induce either structural or numerical chromosome aberrations, did not induce micronuclei in bone marrow cells of mice, had no skin sensitizing potential in the guinea pig maximization test, and had no toxic effects on immuno-toxicological parameters tested at 1000 mg/kg body weight/day for 4 weeks.
In apoptosis, the micronuclei formed from the disrupted DNA repair are released into nutrient-rich interstitial fluid where they are free to clone and proliferate--argued by many to be a probable cancer mechanism.
Nuclear abnormalities in erythrocytes, as micronuclei and nuclear buds (BE), are considered potential biomarkers of genotoxic exposure.