(n. pl.) Those animals in which the protoplasmic mass, constituting the egg, is converted into a multitude of cells, which are metamorphosed into the tissues of the body. A central cavity is commonly developed, and the cells around it are at first arranged in two layers, -- the ectoderm and endoderm. The group comprises nearly all animals except the Protozoa.
Example Sentences:
(1) Phyla as diverse as insects, birds, and mammals possess distinct HRAS and KRAS sequences, suggesting that these genes are essential to metazoa.
(2) The unique structure of these cilia has systematic and phylogenetic significance for the Acoela, and it is argued that ultrastructural characters in general, including characters of organelles, can be validly applied to the phylogeny and systematics of the Metazoa.
(3) In Metazoa single receptory flagellar cells are differentiated; they realize conservatively some receptive molecules that are already prepared by their ancessors--Eukaryota.
(4) Together with previous results that showed the existence of a nonfibrillar collagen in the same species, these data demonstrate that at least two collagen gene families are represented in the most primitive metazoa.
(5) The origin of metazoa implies the passage from an eukarote protozoan to a protozygote ancestor of a metazoan zygote.
(6) RNA synthesis and processing in A. nidulans mitochondria therefore resembles the events occurring in metazoa rather than yeast.
(7) 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.
(8) This is the first report in a nutritional role of peptides in invertebrate metazoa.
(9) In these phylogenies the Ciliophora diverged from the eukaryotic line of descent as a loose phylogenetic grouping during a radiative period that gave rise to the Fungi, the Plantae and the Metazoa.
(10) Analysis of messenger RNA splicing in yeast and in metazoa has led to the identification of an RNA molecule in a lariat conformation.
(11) These findings support the view that Myxosporidia are Metazoa and raise the problem of their origin.
(12) A variety of microorganisms and metazoa was observed, including a baculovirus, gram-negative bacteria, rickettsia-like organisms, amoebae, trypanosomatid flagellates, cephaline gregarines, and microsporidia.
(13) Organisms with defective or with no lymphocytic function are able to live for a certain time while metazoa cannot develop and exist without cells capable of phagocytosis.
(14) Polyploidy--the doubling of chromosome sets of cells caused by a stop of mitosis at different levels of the mitotic cycle--is a phenomenon widely observed in plants, protozoa, metazoa, and animals.
(15) In Metazoa two types of locomotion take place according to the function of regulatory genes: initial flagellar and muscular definitive apparatus.
(16) The presence of spasmins in other Protozoa and in some Metazoa was also investigated.
(17) At this stage, the swimming Metazoa of the thermocline could adapt to a benthic environment on the shelves by developing exoskeletons.
(18) These analyses indicate that (i) the Metazoa is a monophyletic taxon; (ii) the Deuterostomia is a monophyletic taxon; (iii) the Annelida-Mollusca lineage is the sister group of an arthropod subgroup; and (iv) the last common ancestor of the Annelida-Mollusca lineage is most parsimoniously derived from a segmented, hemocoelic ancestor with an open circulatory system.
(19) Tubulin and dinein with ATPh-ase activity are included in the flagella composition of LSS in Eukaryota, actin and miozin--with a high ATPh-ase activity--in composition of LSS myofilaments in ameboid Eukaryota and locomotor musculature in Metazoa.
(20) Comparative evidence on the lack of three important organelles (flagella, Golgi-complex, mitochondria) in cells and organisms at the cellular level of organization has been summarized for all the four eukaryotic kingdoms--Protista, Fungi, Plantae and Animalia (Metazoa).
Metazoan
Definition:
(n.) One of the Metazoa.
Example Sentences:
(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.