(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.
Radial
Definition:
(a.) Of or pertaining to a radius or ray; consisting of, or like, radii or rays; radiated; as, (Bot.) radial projections; (Zool.) radial vessels or canals; (Anat.) the radial artery.
Example Sentences:
(1) Cellular radial expansion was apparently unaffected by exposure to electric fields.
(2) Standard nerve conduction techniques using constant measured distances were applied to evaluate the median, ulnar and radial nerves.
(3) The shape of the nucleus changes from ovoid to a distinctive, radially splayed lobulated structure.
(4) Learning ability was assessed using a radial arm maze task, in which the rats had to visit each of eight arms for a food reward.
(5) The authors describe a new technique for evaluating traumatic conditions to the elbow: the radial head-capitellum view.
(6) Yet in 4 patients in whom no aortic late systolic pressure wave was apparent (group II), nitroprusside did not alter the difference between aortic and radial systolic pressures.
(7) If no other indication to operate occurs, we accept a conservative treatment of the humeral fracture with radial palsy.
(8) The assay systems include : viral infectivity, complement fixing activity, particle counts, radial diffusion titre and single radial haemolysis titre.
(9) The influence of stretch and radial compression on the width of mechanically skinned fibers from the semitendinosus muscle of the frog (R. pipiens) was examined in relaxing solutions with high-power light microscopy.
(10) Peak pressures measured with the RP probe decreased to congruent with50 mm Hg and radial pressure asymmetry vanished.
(11) We report the case of a man with atypical pain and X-rays modifications of the radial tubercle.
(12) The Fel d I RIA was compared with a radial immunodiffusion technique for the determination of allergen levels in several cat extracts and a good quantitative correlation was found.
(13) The results indicate that behavior in transition states maintained by reinforcement contingencies in the radial maze is similar to that maintained by extended chained schedules, despite the fact that some of the stimuli controlling behavior in the maze are absent at the moment behavior is emitted.
(14) In a third experiment, animals were trained 16 days in the same maze configuration and at day 17 they were exposed to the mirror image of the radial maze.
(15) IgE levels in nude mice were estimated by the one-step single radial radiodiffusion method antisera prepared by immunization of guinea pigs with an IgE-rich fraction obtained from sera of normal mice infected with Nippostrongylus brasiliensis and immunized with DNP-ovalbumin in alum gel.
(16) To investigate the topography of the clear zone, we performed four- and eight-incision radial keratotomy in eight cadaver eyes.
(17) The mean values of radial and ulnar components for each pair of homologous fingers separately are also compared.
(18) The patient had associated congenital abnormalities of urethral stricture, hypoplastic thumb, and absent radial pulse.
(19) In 20 out of 32 infants (63%), complete occlusion of the radial artery occurred.
(20) The kininogen level in human serum was estimated by single radial immunodiffusion.