(1) The fertilization reaction of echinoderm eggs (Lytechinus pictus, a sea urchin, and Dendraster excentricus, a sand dollar) was followed with intracellular electrodes.
(2) I describe the anatomy and fine structure of the echinoderm ovary, with emphasis on both the cellular relationships of the germ line cells to the somatic cells of the inner epithelium, and on the neuromuscular systems.
(3) In echinoderms, which stop at interphase, no such a factor has so far been found.
(4) In frogs and mammals, the oocytes are arrested at the second metaphase of meiosis whereas in echinoderms they are blocked later, at the pronucleus stage.
(5) An examination of Antp class homeo box genes in deuterostomes indicates that a chromosomal duplication has taken place in the evolutionary line leading to the vertebrates after the divergence of the echinoderms.
(6) Next, we present some features of the described processes for sugar and amino acid transport in the tubular portion of gastrointestinal tracts of three major invertebrate groups: echinoderms, molluscs, and arthropods.
(7) The emonctory structures, functions and stereotype and their component parts are studied in protists, spongia, coelenterata and coelomata: lower worms, annelids, their hyponeurian descendents (arthropods, molluses) and epineurian descedents echinoderms and protochordates (Stomochordata, Tunicata, Cephalochordata).
(8) The transition from the single creatine kinase locus, characteristic of certain echinoderms, to the two creatine kinase loci which are orthologous to those present in all vertebrates, occurred early in the chordate line.
(9) These features are characteristic of sea urchin (Echinoderm) spines which are composed of ornately formed calcite crystals covered by an epithelium.
(10) The echinoderms Asterias rubens and Solaster papposus (Class Asteroidea) metabolize injected [4(-14)C]cholest-5-en-3beta-ol to produce labelled 5alpha-cholestan-3beta-ol and 5alpha-cholest-7-en-3beta-ol.
(11) Echinoderm oocyte maturation is reviewed and a description of the ultrastructural, biochemical and molecular biological changes thought to occur during this process is presented.
(12) Another round of gene duplication, involving Wnt-3, -5, -7, and -10, occurred after the echinoderm lineage arose, on the ancestral lineage of jawed vertebrates.
(13) Changes in the distribution and organizational state of actin in the cortex of echinoderm eggs are believed to be important events following fertilization.
(14) Small numbers are present in algae, ferns, conifers, sponges, echinoderms, other marine animals, and arthropods.
(15) However, recent work which used colchicine to block microtubule assembly in the eggs of two other echinoderms, S. purpuratus and D. excentricus, has raised serious questions about the generality of this role for spindle microtubules.
(16) It would seem that these epitope regions have been strongly conserved since the epitope region is also present in the phosphoprotein of echinoderm teeth.
(17) Both species differences and species similarities in the agglutination were found in spermatozoa of the echinoderm, the sea urchin and the starfish.
(18) Furthermore, during meiotic maturation in these echinoderm and amphibian oocytes, this is followed by activation of many of the same protein-serine (threonine) kinases that are stimulated when quiescent mammalian somatic cells are prompted with mitogens to traverse from G0 to G1 phase.
(19) One of these fragments contains the active site and is identical at all sequenced residues with the corresponding region from the echinoderm sperm flagellar creatine kinase, and is 96% homologous with both chicken and rat B creatine kinase subunits.
(20) A significant feature of the early development of fertilized echinoderm and amphibian eggs and germinating seed embryos is the utilization of genetic information that has been previously transcribed during oogenesis and seed ripening.
Symmetric
Definition:
(a.) Symmetrical.
Example Sentences:
(1) Bilateral symmetric soft-tissue masses posterior to the glandular tissue with accompanying calcifications should suggest the diagnosis.
(2) In one patient, the pretibial myxedema developed symmetrically half a year after the appearance of endocrine exophthalmos.
(3) A constellation of histologic lesions was identified in brain (diffuse meningoencephalitis with bilaterally symmetrical thalamic necrosis), liver (pericholangiohepatitis), lung (pneumonitis), and spleen (lymphoid hyperplasia); this tetrad is apparently unique to this model system.
(4) For trials in which the target was present in the array, RT functions were roughly symmetric, the shortest RTs being for extreme distractor ratios, and the longest RTs being for arrays in which there were an equal number of each distractor type.
(5) Symmetrical cases (the so-called siamese twins) have an obvious predominance (92.3%).
(6) Sedimentation-velocity experiments indicate the M. elsdenii enzyme (s20,w = 4.95 S) to be essentially globular, while the D. vulgaris enzyme (s20,w = 4.1 S) has a less symmetric shape.
(7) The Soret MCD of the reduced protein is interpreted as th sum of two MCD curves: an intense, asymmetric MCD band very similar to that exhibited by deoxymyoglobin which we assign to paramagnetic high spin cytochrome a3(2+) and a weaker, more symmetric MCD contribution, which is attributed to diamagnetic low spin cytochrome a2+.
(8) In the perineuronal neuropil of large pyramidal neurons (layers V-VI) there appear symmetric synapses with pyramidal cells, dendritic processes and dendritic spines.
(9) After injection of HRP-WGA into the contralateral hippocampus 2% of hilar NPY-i neurons were retrogradely labeled and symmetric NPY-i synapses were found on the cell bodies and dendrites of unstained HRP-WGA labeled neurons.
(10) Pompholyx (Dyshidrosis) is a disease of unknown etiology presenting as symmetrical, vesicular hand and foot dermatitis.
(11) In the degradation reaction, formation of the symmetrically substituted citrate ester of codeine, 1, was found to predominate.
(12) The symmetrical reagent 5,5'-dithiobis-(1-methyltetrazole) activates mitochondrial aldehyde dehydrogenase approximately 4-fold, whereas the smaller related compound methyl l-methyltetrazol-5-yl disulphide is a potent inactivator.
(13) We studied the effect of symmetric, biphasic sinusoidal electromagnetic fields (EMF) (20 Hz, 6 mT) on the differentiation of normal human skin fibroblasts (HH-8), normal human lung fibroblasts (WI38), and SV40-transformed human lung fibroblasts (WI38SV40) in in vitro cultures.
(14) According to X2 (Chi-square) test and asymmetry coefficient (beta 1) it was pointed out that the distribution of menarche in examined schoolgirls was normal and symmetric.
(15) The effect of luminal chloride addition was examined in tubules perfused symmetrically with chloride-free solutions.
(16) Any patient with a fairly symmetrical 'quiet' eye disease, especially if congenital, should be suspected of having an hereditary disease--presumably due to a recessive gene, even if the parents are not consanguineous, but possibly due to a mutation which could prove dominant; a search of the literature in such cases is useful.
(17) In all of the old rats, but not in any of the young ones, symmetric high voltage activity was observed in the frontal pole of the cortex.
(18) Flourescence characteristic of indolamine was seen in 5 pairs of symmetric neurons situated in the anterior part of the worm.
(19) The thiocarboxyl group reacts with diaryl disulfides to give an unsymmetrical acyl disulfide in dimethylformamide (DMF) and a symmetrical diacyl disulfide in aqueous DMF.
(20) The authors describe the radiographic appearance and the investigation techniques for circumscript lipoma in the subcutaneous tissue, in the muscles and for a large diffuse symmetric lipomatosis.