macronucleus


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Related to macronucleus: oral groove

mac·ro·nu·cle·us

(mak'rō-nū'klē-ŭs),
1. A nucleus that occupies a relatively large portion of the cell, or the larger nucleus where two or more are present in a cell.
See also: micronucleus (2). Synonym(s): meganucleus
2. The larger of the two nuclei in ciliates, which governs vegetative metabolic functions and not reproduction.
See also: micronucleus (2). Synonym(s): somatic nucleus, trophic nucleus, trophonucleus

macronucleus

(măk′rō-no͞o′klē-əs, -nyo͞o′-)
n. pl. macronu·clei (-klē-ī′)
The larger of two nuclei present in ciliate protozoans, which controls nonreproductive functions of the cell, such as metabolism.

mac′ro·nu′cle·ar adj.

mac·ro·nu·cle·us

(mak'rō-nū'klē-ŭs)
1. A nucleus that occupies a relatively large portion of the cell, or the larger nucleus where two or more are present in a cell.
2. The larger of the two nuclei in ciliates, which governs vegetative metabolic functions and not reproduction.
See also: micronucleus (2)

macronucleus

or

meganucleus

the larger of two nuclei found in some PROTOZOANS, that is concerned with cell division (see MICRONUCLEUS). It disappears during CONJUGATION and is afterwards reformed from material of micronuclear origin (from the zygote nucleus). It appears to have mainly vegetative functions.
References in periodicals archive ?
This gives an idea of functional constraints of these proteins and their adaptive evolution probably due to nuclear dualism and peculiar organization of chromatin in macronucleus of ciliates.
Entodinium kastamonicum, new species closely resembles Entodinium constrictum Dehority 1974, in shape of the body and macronucleus and the position of contractile vacuole.
During most of a cell's existence, the micronucleus is inactive, and the macronucleus directs the business of making proteins.
One of the next experiments I have planned is to look at which MDSs are connected throughout the developing macronucleus.
Interstitial telomeres are hotspots for illegitimate recombination with DNA molecules injected into the macronucleus of Paramecium primaurelia.
Unfortunately for our purposes, the experiments were typically without large-population controls, and even mass [TABULAR DATA FOR TABLE 1 OMITTED] cultures of some ciliates are known to degrade without some way of reconstituting the macronucleus (Takagi and Yoshida 1980).
coli has a direct life cycle with both the trophozoite and cyst stages containing a large macronucleus and smaller micronucleus.
The teardrop shaped basophilic ciliate (10.15 [micro]m x 5 [micro]m) has a dense polymorphic macronucleus and normally occupies an intraluminal or intraepithelial location within the digestive gland in P.
A micronucleus holds the creature's full set of genes, while a macronucleus has a restricted set that carries only essential living instructions.
From the Giemsa-stained specimens the macronucleus also presents a horseshoe-shaped 43.2 [+ or -] 4.7 (32-49, 26) of external diameter and 11.0 [+ or -] 2.2 (7-17, 26) thickness.
Macronucleus The large kidney-shaped nucleus found in some ciliates.