(n.) A genus of herbs with compound white or bluish flowers; starwort; Michaelmas daisy.
(n.) A plant of the genus Callistephus. Many varieties (called China asters, German asters, etc.) are cultivated for their handsome compound flowers.
Example Sentences:
(1) Microscopic examinations of eggs stained with aceto-orcein or the DNA fluorochrome bisbenzimide and direct observations on isolated sperm aster complexes show that halothane induces polyspermy (multiple sperm entry) when present at fertilization.
(2) Second, the bulk of the vegetally located myoplasm moves with the sperm aster towards the future posterior pole, but interestingly about 20% remains behind at the anterior side of the embryo.
(3) The CTR2611 antigen is present in the center of each of these asters.
(4) Cytoplasmic asters were observed at all doses tested.
(5) RNase alters the in vitro assembly of spindle asters in homogenates of meiotically dividing surf clam (Spisula solidissima) oocytes.
(6) ASTER is an integration of the ACQUIRE (AQUatic toxicity Information REtrieval system) and QSAR (Quantitative Structure Activity Relationships) systems.
(7) The data indicate that meiotic spindle assembly is dependent on ongoing protein synthesis in the cumulus-enclosed hamster oocyte; in contrast, chromatin condensation and aster formation are not as sensitive to protein synthesis inhibitors during meiotic resumption.
(8) The eggs of the surf clam Spisula solidissima were artificially activated, homogenized at various times in cold 0.5 M MES buffer, 1mM EGTA at pH 6.5, and microtubule polymerization was induced by raising the temperature to 28 degrees C. In homogenates of unactivated eggs few microtubules form and no asters are observed.
(9) 101:289-316) used computer simulations to show that long-range signals from the asters, varying inversely as various powers of distance, produce summed effects that are minima at the equator of spherical cells.
(10) Microinjection of SPN-3 antibody into taxol-treated mitotic PtK2 cells causes disruption of the asters as judged by tubulin staining of the same cells.
(11) Furthermore, numerous cytoplasmic asters become visible in the cytoplasm.
(12) This is accompanied by the apparent shortening of the microtubules running between the asters.
(13) Mesomere-mesomeres (which divide equally) and macromere-micromeres (which divide unequally) are compared in terms of their asters (both mitotic and so-called interphase asters), spindle apparatus, and contractile ring.
(14) Within 15 min after incubation in D2O, numerous fine centrosomal foci are detected, and they organize a connected network of numerous asters which fill the entire egg.
(15) In the normal two-celled embryos of various pulmonate molluscs, the orientation of spindles characteristic of metaanaphase is being frequently established gradually, in the process of transition from pro- to metaphase accompained by the growth of spindle and asters.
(16) Colcemid-treated prometaphase cells lysed into polymerization-competent tubulin develop large asters in the region of the centrioles and short tubules at kinetochores, making it unlikely that all microtubule formation in lysed cell preparations is dependent on tubulin addition to short tubule fragments.
(17) They located in euchromatin regions of thymus lymphocytes, with a characteristic aster-like immunofluorescence pattern, and on the border of condensed chromatin areas by deposition of immunogold particles in ultrathin sections of thymus.
(18) We conclude first, that centrioles contain RNA which is required for initiation of aster formation, and second, that the centriole activity or ability to assemble a mitotic aster is separable from the basal body activity, or ability to serve directly as a template for microtubule growth.
(19) When injected into fertilized eggs at streak stage, the tubulin was quickly incorporated into each central region of growing asters.
(20) The asters then divide to form a transient tetrapolar figure.
Mitosis
Definition:
(n.) See Karyokinesis.
Example Sentences:
(1) MAF-G activity was inhibited by mitomycin C and colchicine, which inhibit DNA synthesis and mitosis, respectively, but not by 2-deoxy-D-glucose, an inhibitor of glucose metabolism.
(2) With the stimulated liver being irradiated, the number of cells synthetizing DNA and entering into mitosis was seen reduced almost twice, whereas DNA synthesis and entering into mitosis were delayed, resp., by 4 and 6 hours.
(3) The distribution of cells at the stage of DNA synthesis and mitosis in all the parietal peritoneum speaks of the absence of special proliferation zones.
(4) Isoproterenol [IC 50 approximately 1 X 10(-9) M], prostaglandins, dibutyryl cyclic AMP [IC 50 approximately 2 X 10(-5) M], papaverine, theophylline and 5' AMP were inhibitory in the assay, whereas dibutyryl cyclic GMP and the cholinergic stimulator carbamylcholine either stimulated or had no effect on mitosis.
(5) Despite severe defects in the 1st or 2nd meiotic spindles in all mutants, no effect on mitosis was observed.
(6) Since transcription does not take place during mitosis, the amount of protooncogene products is rapidly decreased (they are extremely unstable).
(7) The role played by macrophages in two effects of lipopolysaccharide (LPS) on the immune system of the mouse-substitution for helper T cells and induction of B-cell mitosis-has been investigated.
(8) The results obtained allow to conclude that heterophasic condition of the fused cells is one of the causes of pathological mitosis of polykaryons and of their death.
(9) The effect of intracerebroventricular injection of the mitosis inhibitor colchicine on expression of mRNA for nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), and neurotrophin 3 was studied in the rat brain with in situ hybridization.
(10) The major events of mitosis have traditionally been considered to represent two distinct pathways and have been studied by two separate groups of workers.
(11) The V79 cells were treated for 30 min and in general, loss of a stainable spindle could be demonstrated at slightly higher concentrations than c-mitosis.
(12) However, unlike animal cell calmodulin, endosperm calmodulin appears to associate with kinetochore microtubules throughout mitosis, which suggests a specialized role for higher plant calmodulin in the regulation of kinetochore microtubule dynamics.
(13) This finding is directly opposed to that in rat skin where mitosis is stimulated.
(14) The restriction enzymes were introduced by electroporation into exponentially growing cells during the second replication cycle in bromodeoxyuridine, and SCEs were analyzed at mitosis.
(15) The absence of these mRNAs in mitosis and their disappearance at 4 hr and later in meiosis suggest that the rec7 and rec8 gene products may be involved primarily in the early steps of meiotic recombination in S. pombe.
(16) The distribution of bone marrow cells within the cell cycle was determined by flow microfluorometry and 7 hours after treatment with vincristine consisted of 69% in G1, 21% in S, and 9% in mitosis.
(17) In contrast, in HeLa, a human epithelial cell, keratin-containing IFB appear to dissemble as cells enter mitosis (Franke, W. W., E. Schmid, C. Grund, and B. Geiger, 1982, Cell, 30:103-113).
(18) After administration of vinblastine, a drug blocking mitosis in metaphasis, the percentage of lymphoblasts decreases whereas the percentage of X cells increases.
(19) The ultrastructure study, done before the 19th week ("pretumor" phase) confirms some previous observations (increase in the zone of mitosis, secretory changes, mutation producing effects).
(20) Still, they gave valuable information in relation to environmental screening; thus, the finding of c-mitosis may indicate risks of aneuploidy.