(1) Because ctenophore and all other known metazoan mtDNA is circular, the shared occurrence of linear mtDNA in three of the four cnidarian classes suggests a basal position for the Anthozoa within the phylum.
(2) Cloning of three Antennapedia-related sequences from cnidarians provides evidence of ancient roles for homeobox genes early in metazoan evolution.
(3) Cnidocytes, the stinging cells of cnidarians, discharge nematocysts in response to physical contact accompanied by the stimulation of specific chemoreceptors.
(4) It is suggested that they may also be present as predominant components in nematocysts of other cnidarian species and thus might represent a class of compounds which is characteristic for a whole phylum of the animal kingdom.
(5) The principal sources of these agents are bacteria, higher fungi, cnidarians (coelenterates) and the venoms of snakes, insects and other arthropods.
(6) The presence of cholecystokinin (CCK), originally isolated from porcine small intestine, has been reported in a diversity of invertebrates ranging, from cnidarians to protochordates, but so far, not in echinoderms.
(7) Cnidarians arose from a protist ancestry different from the second group, the Bilateria.
(8) In these trees, cnidarians (Radiata) seemed to have evolved independently from the Bilateria, which is in contradiction with the general evolutionary view.
(9) It is present in all cnidarians and can be isolated without enzyme treatment.
(10) The ganglion has been compared to the nervous systems in cnidarians, some spiralians, and especially other hemichordates, echinoderms, and chordates; it is found to be of primitive rather than degenerate nature.
(11) We report the nucleotide sequence of eveC, a cnidarian eve-class homeobox; this is the first homeobox to be identified in any diploblastic organism, and is only the second eve-class in an invertebrate.
(12) We previously characterized annexin XII from the freshwater cnidarian Hydra vulgaris (Schlaepfer, D. D., D. A. Fisher, M. E. Brandt, H. R. Bode, J. Jones, and H. T. Haigler.
(13) This report describes the cloning and sequencing of both cDNA and genomic clones of GFP from the cnidarian, Aequorea victoria.
(14) Eggs from all of the animals considered are covered by complex vitelline envelopes except those of cnidarians.
(15) The application of molecular techniques to cnidarians can provide important insights into developmental processes and phylogenetic relationships both within the phylum Cnidaria and among the eumetazoa.
(16) A new system is described for the study of ECM-tissue interactions, using the ECM (called mesogloea) of various cnidarians and isolated striated muscle and endodermal tissue of jellyfish.
(17) gamma-Glutamyltransferase activity was studied in extracts of the cnidarian Hydra attenuata.
(18) The results show that: polyps under normal conditions have similar regeneration patterns, regardless of individual variability; and ATxII, a neurotoxin of cnidarian origin, produces a statistically significant increase in the Tentacle Regeneration Index.
(19) In the context of earlier observations in cnidarians, these cytological features suggest a sensory as well as a modulatory function for 5-HT in Renilla koellikeri.
(20) Specifically, sperm eggs from cnidarians, echinoderms, decapod crustaceans, ascidians, lampreys, bony fishes, and amphibians are discussed.
Hydra
Definition:
(n.) A serpent or monster in the lake or marsh of Lerna, in the Peloponnesus, represented as having many heads, one of which, when cut off, was immediately succeeded by two others, unless the wound was cauterized. It was slain by Hercules. Hence, a terrible monster.
(n.) Hence: A multifarious evil, or an evil having many sources; not to be overcome by a single effort.
(n.) Any small fresh-water hydroid of the genus Hydra, usually found attached to sticks, stones, etc., by a basal sucker.
(n.) A southern constellation of great length lying southerly from Cancer, Leo, and Virgo.
Example Sentences:
(1) As an extension of the previous study which indicated that mesoglea is a primitive basement membrane which has retained some characteristics of interstitial extracellular matrix, the present study was undertaken to analyze the role of mesoglea components during head regeneration in Hydra vulgaris.
(2) Using serial-sectioning techniques for conventional transmission and high-voltage electron microscopy, we characterized the ultrastructural features and synaptic contacts of the sensory cell in tentacles of Hydra.
(3) The neuron differentiation pathway in hydra is usually assumed to be the following.
(4) The extent of the growth changes in maximal work output during 10 s (MWO10), 30 s (MWO30), and 90 s (MWO90) of maximal repetitive knee flexions and extensions assessed on a modified Hydra-Gym machine was investigated in 84 boys and 83 girls, 9-19 yr of age.
(5) Substance P-like immunoreactivity was found in Hydra attenuata mainly but not exclusively in the nerve and interstitial cells, localized in the cytoplasm and on the cell surface membranes.
(6) Hydrozoans such as Hydra vulgaris, as with all classes of Cnidaria, are characterized by having their body wall organized as an epithelial bilayer with an intervening acellular layer termed the mesoglea.
(7) These results are the first demonstration that the dense-cored vesicles of Hydra neurons contain a neuropeptide.
(8) Nematocyte differentiation from interstitial stem cells in hydra occurs in a highly position-dependent manner along the body axis.
(9) The presence of Arg-Phe-amide (RFamide)-like peptides in dense-cored vesicles in neurons of the peduncle of Hydra was demonstrated by immunogold electron microscopy.
(10) History will judge Syria’s descent into a hydra-headed war as a stain on the world’s conscience.
(11) The multiple manifestations of systemic lupus erythematosus recall the ancient Greek monster the Hydra.
(12) Hydra) has raised some interesting evolutionary questions as to the function of intragranular nucleotides.
(13) Captain America kicking open the door of what looks like a European mountain fortress suggests the Nazi offshoot Hydra might be rearing its many ugly heads once again.
(14) Intact hydra treated for 24 h with oligomycin gradually lose their head structures and the distal ends form feet.
(15) This substance is specific for the foot as evidenced by the following findings: (1) It is present in the animal as a steep gradient descending from foot to head, paralleling the foot-forming potential of the tissue (2) It does not accelerate head regeneration, nor do the head factors of hydra discovered by Schaller (1973) and Berking (1977) accelerate foot regeneration.
(16) This study concerns application of the Hydra attenuata assay to detect the developmental toxicity potential of various aqueous samples.
(17) Feeding behavior in hydra is initiated by the association of glutathione (GSH) with a putative external chemoreceptor.
(18) Because it is self-inflicted, hydra-headed and increasingly beyond our control, both politically and economically, at a time when Britain is losing friends fast by peeing on their chips.
(19) The tentacles in hydra have characteristics of both spacing patterns and number-regulating patterns in that their number under some circumstances changes with the size of the animal and under others does not.
(20) Every epithelial cell is continuously displaced with neurons toward either head or foot in an adult hydra.