micronucleus


Also found in: Dictionary, Encyclopedia, Wikipedia.

micronucleus

 [mi″kro-noo´kle-us]
1. in ciliate protozoa, the kinetoplast, the smaller of two types of nucleus in each cell, which functions in sexual reproduction.
2. a small nucleus.

mi·cro·nu·cle·us

(mī'krō-nū'klē-ŭs),
1. A small nucleus in a large cell, or the smaller nuclei in cells that have two or more such structures.
See also: macronucleus (2).
2. The smaller of the two nuclei in ciliates dividing mitotically and bearing specific inheritable material.
See also: macronucleus (2). Synonym(s): gametic nucleus, germ nucleus, gonad nucleus, karyogonad, reproductive nucleus

micronucleus

/mi·cro·nu·cle·us/ (-noo´kle-us)
1. in ciliate protozoa, the smaller of two types of nucleus in each cell, which functions in sexual reproduction; cf. macronucleus.
2. a small nucleus.

micronucleus

[-no̅o̅′klē·əs]
1 a small nucleus.
2 the smaller of two nuclei in some protozoa. It functions in sexual reproduction. Compare macronucleus.

mi·cro·nu·cle·us

(mī'krō-nū'klē-ŭs)
1. A small nucleus in a large cell, or the smaller nuclei in cells that have two or more such structures.
2. The smaller of the two nuclei in ciliates dividing mitotically and bearing specific inheritable material.
See also: macronucleus (2)

micronucleus

the smaller of two nuclei found in some protozoans which is concerned with cell division. Compare MACRONUCLEUS.

micronucleus

1. in ciliate protozoa, the kinetoplast, the smaller of two types of nucleus in each cell, which functions in sexual reproduction.
2. a small nucleus.
3. nucleolus.
References in periodicals archive ?
The micronucleus assay with mouse peripheral blood reticulocytes using acridine orange-coated slides.
Micronucleus investigation in human buccal epithelial cells of gutkha users.
The Human MicroNucleus Project: an international collaborative study on the use of micronucleus technique for measuring DNA damage in humans.
Second, it is out of sync: the micronucleus keeps trying to replicate its chromosomes long after replication of the other chromosomes was completed.
Radioprotective effect of extract from Spirulina platensis in mouse bone marrow cells studied by using the micronucleus test.
Micronucleus analysis: The lymphocytes were cultured according to the method of Fenech and Morley (13).
Higher plants are good genetic models for the assessment of the environmental pollutants, not only due to the sensitivity in evaluation of the genotoxicity of dangerous/harmful chemicals in different environments for years, but also to the potential of assessing numerous genetic endpoints, varying from point mutations to chromosome aberrations and micronucleus formation in cells of different organs and tissues, such as leaves, roots and pollen [5-7].
The mouse micronucleus test is a significant addition because it is an animal test while up to now only in vitro testing was required.
The current International Conference of Harmonization of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH) recommends a battery of tests for the registration of pharmaceuticals, requiring an assessment of mutagenicity in a bacterium, such as the Ames test, plus an in vitro test with cytogenetic evaluation of chromosomal damage in mammalian cells, such as the micronucleus test or an assessment of mutagenicity in mammalian cells, such as the mouse lymphoma assay.
The micronucleus test, is an in vivo and in vitro short-time screening test, developed by Schmid (1975) and Handle (1973) is widely used to detect genotoxic effects (He et.
These nine articles detail research into the effects of such toxins on certain species or locales, with topics including oxidative stress as a component of transition metal toxicity to fish, pharmaceuticals and their effects on humans and aquatic life, microbial and chemical assays that determine the origin of fecal pollution and the presence of waterborne pathogens, effects of pesticides on aquatic organisms, heavy metals in marine sponges, fine scale spatial and temporal variations in the structure and function of aquatic microbial communities, a micronucleus test for aquatic toxicology, colonization of water systems in urban environments of northern Germany by Legionella SPP and Pseudomonas SPP, and ferrinin and labile iron pools in limpets.