(n.) A peculiar rounded body lying near the nucleus of a cell. It is regarded as the dynamic element by means of which the machinery of cell division is organized.
Example Sentences:
(1) This apparent lack of centrosomal staining was not due to problems associated with penetration of the antibody probes, since staining adjacent to and within the centriolar cylinder was observed when phosphoprotein antigens recognized by the MPM-2 antibody were localized.
(2) Control-operated cells with centrosomes left in the karyoplast progress through the cell cycle, duplicate the centrosome, and form clonal cell colonies.
(3) PCC-kinetochores display a typical trilaminar morphology, associate with microtubules and show movement towards the centrosome.
(4) However, only a few proteins are extracted by these treatments and the centrosome ultrastructure is not affected.
(5) Two high titer sera were identified that reacted with HeLa, CHO, and PtK2 centrosomes by immunofluorescence, although the fluorescent patterns that were obtained using the two antisera were separate and distinct.
(6) They suggest that the centrosome cycle can be blocked when the centrioles are prevented from separating into a nonlinear configuration, a step which might be critical for the initiation of procentriole budding.
(7) The developmental sequence of events in marginal band formation entails microtubule nucleation at the centrosome, followed by microtubule elongation, consolidation of loose parallel microtubules into a compact bundle, and microtubule association with the cell membrane.
(8) This treatment allows observation of the stages of the centrosome cycle--separation, division, and bipolarization--while the chromosomes are arrested in metaphase.
(9) These results indicate that both microtubules and microfilaments may be involved in determining centrosome shape during the syncytial mitoses which lead to the formation of the blastoderm in early Drosophila embryos.
(10) Colocalization studies with MPM-2 revealed that centrosomes were always phosphorylated.
(11) The relationship of the centrosome in B. rubinellus to that in other organisms and the role of the cytoplasmic microtubules are discussed.
(12) (3) The functional loss of the maternal centrosome is not due to its cortical location.
(13) 2h after enucleation the centrosome structure in the cytoplasts did not differ from that in normal cells.
(14) Here we show that centrosomes inactivated by urea are functionally complemented in frog egg extracts.
(15) Cold treatment of embryos during the cellularization of the blastoderm results in marked fragmentation of the centrosomes, but nucleating capacity is preserved.
(16) The microtubules originated at prominent centrosomes located close to the apical surface of each cap nucleus.
(17) In addition control cells and cells heated at 45.5 degrees for 15 min were immediately subjected to a cell fractionation procedure that yielded partially purified centrosome preparations.
(18) This confirms a model in which, at prometaphase, fast probing centrosomal MTs are grabbed by the kinetochores, where tubulin incorporation then takes place.
(19) There was, however, a reduction of wound re-endothelialization and an associated reduction in the proportion of cells with centrosomes redistributed toward the wound edge.
(20) Remarkably mouse sperm do not appear to have the centrosomal antigen and instead centrosomes are found in the unfertilized oocyte.
Nucleus
Definition:
(n.) A kernel; hence, a central mass or point about which matter is gathered, or to which accretion is made; the central or material portion; -- used both literally and figuratively.
(n.) The body or the head of a comet.
(n.) An incipient ovule of soft cellular tissue.
(n.) A whole seed, as contained within the seed coats.
(n.) A body, usually spheroidal, in a cell or a protozoan, distinguished from the surrounding protoplasm by a difference in refrangibility and in behavior towards chemical reagents. It is more or less protoplasmic, and consists of a clear fluid (achromatin) through which extends a network of fibers (chromatin) in which may be suspended a second rounded body, the nucleolus (see Nucleoplasm). See Cell division, under Division.
(n.) The tip, or earliest part, of a univalve or bivalve shell.
(n.) The central part around which additional growths are added, as of an operculum.
(n.) A visceral mass, containing the stomach and other organs, in Tunicata and some mollusks.
Example Sentences:
(1) Microionophoretically applied excitatory amino acids induced firing of extracellularly recorded single units in a tissue slice preparation of the mouse cochlear nucleus, and the similarly applied antagonist 2-amino-5-phosphonovalerate (2APV) was demonstrated to be a selective N-methyl-D-aspartate (NMDA) receptor antagonist.
(2) The present results provide no evidence for a clear morphological substrate for electrotonic transmission in the somatic efferent portion of the primate oculomotor nucleus.
(3) In the caudal spinal trigeminal nucleus (Vc), the collaterals of one half of the periodontium afferent fibers terminated mainly in lamina V at the rostral and middle levels of Vc.
(4) It is concluded that in the mouse model the ability of buspirone to reduce the aversive response to a brightly illuminated area may reflect an anxiolytic action, that the dorsal raphe nucleus may be an important locus of action, and that the effects of buspirone may reflect an interaction at 5-hydroxytryptamine receptors.
(5) hypoglossal nucleus), whereas in other areas the angiotensinogen gene was expressed only in a certain population of glial cells.
(6) Local application of 8-OH-DPAT (0-5 micrograms) into the median raphe nucleus, facilitated male rat sexual behavior, as evidenced by a decrease in number of intromissions preceding ejaculation and in time to ejaculation.
(7) In addition, lightly immunostained cells were distinguished in the caudal portion of the hypothalamic arcuate nucleus, area of tuber cinereum, retrochiasmatic area, and rostral portion of the paraventricular thalamic nucleus after colchicine treatment.
(8) Arising of the nucleus from a polyheteronomous nucleoid of proeukaryotes.
(9) It is possible that the IgE that linked abnormally with the propofol had specific binding sites for the phenyl nucleus and the isopropyl groups, which are present in propofol and many other drugs.
(10) We conclude that neuronal activities in the region of the retrofacial nucleus are important both in the integration of stimuli from the central chemoreceptors and in defining the discharge patterns of respiratory neurons.
(11) A 68 year-old man with a history of right thalamic hemorrhage demonstrated radiologically in the pulvinar and posterior portion of the dorsomedian nucleus developed a clinical picture of severe physical sequelae associated with major affective, behavioral and psychic disorders.
(12) While the heaviest anterogradely labeled ascending projections were observed to the contralateral ventral posterolateral nucleus of the thalamus, pars oralis (VPLo), efferent projections were also observed to the contralateral ventrolateral thalamic nucleus (VLc) and central lateral (CL) nucleus of the thalamic intralaminar complex, magnocellular (and to a lesser extent parvicellular) red nucleus, nucleus of Darkschewitsch, zona incerta, nucleus of the posterior commissure, lateral intermediate layer and deep layer of the superior colliculus, dorsolateral periaqueductal gray, contralateral nucleus reticularis tegmenti pontis and basilar pontine nuclei (especially dorsal and peduncular), and dorsal (DAO) and medial (MAO) accessory olivary nuclei, ipsilateral lateral (external) cuneate nucleus (LCN) and lateral reticular nucleus (LRN), and to a lesser extent the caudal medial vestibular nucleus (MVN) and caudal nucleus prepositus hypoglossi (NPH), and dorsal medullary raphe.
(13) In contrast to this, adrenalectomy decreased ANP levels markedly in the organum vasculosum laminae terminalis and preoptic periventricular nucleus, which are reportedly involved in the central regulation of salt and water homeostasis.
(14) The shape of the nucleus changes from ovoid to a distinctive, radially splayed lobulated structure.
(15) Immunocytochemical analysis also suggested that bFGF immunoreactivity was present in the nucleus as well as the cytoplasm of astrocytes and CA2 neurons.
(16) The effect of Y-516 on the hyperactivity induced by dopamine injected bilaterally into the nucleus accumbens was compared with those of clocapramine (CCP), haloperidol (HPD) and chlorpromazine (CPZ).
(17) Moderately differentiated tumor revealed a wider range of nucleus size, less clustering (coefficient--3.59) and more hyperchromatic (70.1%) and "bare" (49.4%) nuclei and large nucleoli (22.2%).
(18) The majority of intensively stained and densely packed cells have been observed in tv nucleus.
(19) Following electrical stimulation of the hypothalamic paraventricular nucleus (PVN) area, 21% of the neurons were orthodromically excited, 6% were inhibited and 2.5% were antidromically activated.
(20) Proenkephalin A-related immunoreactive neuronal perikarya were detected in the central gray, reticular formation, nucleus raphes, trapezoid body, nucleus parabrachialis lateralis and medialis, nucleus spinalis nervi trigemini, nucleus dorsalis nervi vagi, and in the nucleus tractus solitarii.