(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) There is also some evidence that this exists in metazoan cells and is perhaps involved in neoplastic transformation.
(3) The origin of metazoa implies the passage from an eukarote protozoan to a protozygote ancestor of a metazoan zygote.
(4) The protein genes are the same as 12 of the 13 protein genes found in other metazoan mtDNAs: Cyt b, cytochrome b; COI-III, cytochrome c oxidase subunits I-III; ATPase6, Fo ATPase subunit 6; ND1-6 and 4L, NADH dehydrogenase subunits 1-6 and 4L: a gene for ATPase subunit 8, common to other metazoan mtDNAs, has not been identified in nematode mtDNAs.
(5) Yeast counterparts of the metazoan spliceosomal snRNAs (U1, U2, U4, U5 and U6) have been identified but, with the exception of U6, the yeast snRNAs are larger and sequence similarity is limited to short regions.
(6) PCR also proved to be a rapid method for identifying homeobox sequences from diverse metazoan species.
(7) The earliest metazoans, when symmetrical at all, were probably radial in symmetry.
(8) The most probable hypothesis is that of a symbiotic origin of the first zygote by association of two protists one signifying a spherical oocell and the other a flagellated spermatozoan; this could be the first step of the metazoan ontogenesis and therefore also of the phylogenesis.
(9) A summary of the metazoan parasites reported from A. rufa is included.
(10) Comparison of the sequences obtained from the different species indicate that the metazoan lineages all appear to have arisen at approximately the same time and significantly later than the time of divergence of yeast from the common ancestor of the Metazoa.
(11) Movements, manifest as changes in cell arrangements and shape, are an integral part of metazoan development.
(12) The role of convergent extension in gastrulation of other amphibians and other metazoans and its significance to related problems in early development are discussed.
(13) The structure of Pit-1 and its recognition elements suggests that metazoan tissue phenotype is controlled by a family of transcription factors that bind to related cis-active elements and contain several highly conserved domains.
(14) We also mutagenized a portion of the yeast core subdomain, a region conserved in primary and secondary structure among several yeast species but absent from the much smaller metazoan U1 molecule.
(15) Although multiple infections often confounded interpretation it was concluded that the major infectious diseases, of approximately equal importance, were coccidiosis, bacterial septicaemia with Gram-negative organisms, and metazoan parasitism including ascariasis and pentastomiasis.
(16) This work demonstrates that conversion takes place at an appreciable frequency between tandem repeats in metazoan germline.
(17) PI did not cochromatograph with any of the catecholamines commonly thought to be involved in immune responses of dipterans against metazoan parasites, suggesting that it may be a unique substrate for these reactions.
(18) Formation of the 3' end of U1 and U2 small nuclear RNA (snRNA) precursors is directed by a conserved sequence called the 3' box located 9 to 28 nucleotides downstream of all metazoan U1 to U4 snRNA genes sequenced so far.
(19) Cloning of three Antennapedia-related sequences from cnidarians provides evidence of ancient roles for homeobox genes early in metazoan evolution.
(20) Implications of a replicon basis for chromatin structure-function and the evolution of metazoan organisms are considered.
Protozoan
Definition:
(a.) Of or pertaining to the Protozoa.
(n.) One of the Protozoa.
Example Sentences:
(1) This ability may be associated with virulence, because an attenuated strain of L. pneumophila fails to multiply within this protozoan, whereas a virulent strain increases 10,000-fold in number when coincubated with T. pyriformis.
(2) Upon incubation with fluoresceinylated neoglycoproteins, isolated macronuclei from the ciliated protozoan Euplotes eurystomus display different labelling patterns depending on the nature of the sugar bound to the neoglycoproteins.
(3) It is suggested that this early immune maturity may play a role in the hardiness of WAD goats and in their relative resistance to helminth and protozoan infection as compared with local sheep.
(4) We compared the molecular nature of the rat brain opiate receptor with that of the invertebrate leech, Haemopis marmorata, and the protozoan, Tetrahymena, in order to examine the issue of apparent receptor heterogeneity with respect to biochemical structure.
(5) The protozoan parasite Trypanosoma cruzi is able to replicate in the cytoplasm of primary resident macrophages, but is killed by activated macrophages.
(6) Axenic H. vermiformis strain CDC-19 has been deposited with the American Type Culture Collection (ATCC 50237) and should prove useful in the study of protozoan-bacterial interaction.
(7) No cross reactions were observed in sera immune to other protozoan, helmintic and bacterial infections, although some cross reactivity was seen in P. falciparum immune sera.
(8) Alveolar macrophages from the 3 groups of subjects had similar limited microbicidal ability for the obligate intracellular protozoan, Toxoplasma gondii, and similar numbers of elastase receptors and affinity for elastase.
(9) DNA-dependent RNA polymerase from blood forms and culture forms of the parasitic protozoan Trypanosoma brucei was resolved into multiple peaks of activity by DEAE-Sephadex chromatography.
(10) A list is provided of the naturally or experimentally Aedes aegypti transmitted arboviruses (103), protozoans (5) and filaria (20).
(11) A 50% inhibition of the biosynthesis of dihydrosterculate is observed in the presence of 4 microM 10-thiastearate in the protozoan growth medium, but little effect is seen on the distribution of the other fatty acids.
(12) Protozoan species abundance was reduced to less than half by Zn but was unaffected by snails.
(13) Its presence in Giardia is consistent with the view that ARF emerged before the divergence of this protozoan from other eukaryotes (approximately 1.5 billion years ago), and that an ARF-like protein may have been the ancestor of several other classes of signal-transducing guanine nucleotide-binding proteins, including the alpha subunits of the heterotrimeric G proteins.
(14) We have found that the anaerobic protozoan parasite Giardia lamblia is incapable of de novo pyrimidine metabolism, as shown by its inability to incorporate orotate, bicarbonate, and aspartate into the pyrimidine nucleotide pool.
(15) Entamoeba coli was the most frequent protozoan (23.5%).
(16) In the macronucleus of the ciliated protozoan, Tetrahymena pyriformis GL, the genes coding for 17S and 25S rRNA exist as free, extrachromosomal molecules.
(17) Faecal samples were collected from 20 pigs in 4 age groups in randomly selected piggeries, and examined for the presence of eggs of helminth parasites and protozoan cysts.
(18) Nucleoside salvage pathways are vital to the parasitic protozoan Trypanosoma cruzi, and have become important targets in the development of new chemotherapeutic agents against this organism.
(19) It is now well established that pathogens such as viruses, fungi bacteria and protozoans can have profound effects on the dynamics of their invertebrate host populations.
(20) Leishmania donovani, the protozoan causing visceral leishmaniasis, is an obligate intracellular parasite of mammalian macrophages.