(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.
Starfish
Definition:
(n.) Any one of numerous species of echinoderms belonging to the class Asterioidea, in which the body is star-shaped and usually has five rays, though the number of rays varies from five to forty or more. The rays are often long, but are sometimes so short as to appear only as angles to the disklike body. Called also sea star, five-finger, and stellerid.
(n.) The dollar fish, or butterfish.
Example Sentences:
(1) The kinetics of the membrane current during the anomalous or inward-going rectification of the K current in the egg cell membrane of the starfish Mediaster aequalis were analyzed by voltage clamp.
(2) Using tubulin immunostaining, we found that 6-DMAP did not affect the cortical microtubules and resting female centrioles of prophase-arrested starfish oocytes, whereas it induced a precocious disappearance of spindle fibers when applied to hormone-stimulated oocytes.
(3) When he sits back at the piano and plays Raspberry Beret and Starfish and Coffee and Girls and Boys, they’re beside themselves, and understandably so: he sounds magnificent.
(4) The cockle Cardium tuberculatum responds with a typical escape movement (jumping by foot contractions) when touched by a starfish.
(5) Since these characteristics of the starfish egg poly(A)+ RNA are similar to those of cyclin mRNAs from sea urchin and surf clam eggs, we synthesized a 50-mer antisense-cyclin oligonucleotide probe coding for a part of the sea urchin cyclin cDNA and used this to screen starfish RNA.
(6) The cellular events that take place during reconstruction of larval forms from dissociated embryonic cells of the starfish are investigated by thick and thin sections.
(7) Primary afferent electrical activity can be recorded from the chemoreceptors on the mantle margin that are responsive to starfish scent and also from other physiologically distinct receptors that are responsive to contact with starfish tube feet.
(8) A cDNA clone encoding starfish cyclin B has been isolated and its sequence determined.
(9) The changes in activity of a cytoplasmic maturation-promoting factor (MPF), capable of inducing resumption of meiosis when injected into starfish oocytes, were examined during mouse oocyte maturation.
(10) 1-Methyladenine (1MeAde) is the naturally occurring maturation-inducing hormone of starfish oocytes.
(11) The marine gastropods Acmaea (Collisella) limatula and Acmaea (Notoacmea) scutum respond to distant predatory starfish (i.e.
(12) "There are a number of threats facing the reef, including climate change, coastal developments, agricultural runoff, ocean acidification and outbreaks of the crown-of-thorns starfish.
(13) Fatty acid hydroperoxides (lipoxygenase products) are metabolized to allene oxides by a type of dehydrase that has been detected in plants, corals, and starfish oocytes.
(14) Ross said researchers have identified four new species of fish, a new type of starfish and several new species of crustaceans living in the deepwater reefs.
(15) An assessment by the Great Barrier Reef Marine Park Authority cited climate change as the leading threat to the coral ecosystem, with pollution, extreme weather events, and a plague of coral-eating starfish also contributing to its malaise.
(16) This has come about because links have been established between two independent areas of research, one based on a genetic approach using the fission yeast Schizosaccharomyces pombe and the second based on a biochemical approach using Xenopus and starfish oocytes.
(17) In the presence of 1 mM hydroxyurea, fertilized eggs of the starfish, Asterina pectinifera, cleaved up to the 256-cell stage and decomposed before blastulation.
(18) Porcine brain tubulin labeled with fluorescein isothiocyanate (FITC) was able to polymerize by itself and co-polymerize with tubulin purified from starfish sperm flagella.
(19) Although caffeine, theophylline, and theobromine supposedly inhibit maturation of oocytes, studies using the starfish oocyte showed that theobromine does not inhibit maturation and the inhibition caused by caffeine and theophylline is reversible.
(20) The acrosome reaction of spermatozoa from the starfish Marthasterias glacialis was induced with the ionophore A23187.