What's the difference between cleavage and micromere?
Cleavage
Definition:
(n.) The act of cleaving or splitting.
(n.) The quality possessed by many crystallized substances of splitting readily in one or more definite directions, in which the cohesive attraction is a minimum, affording more or less smooth surfaces; the direction of the dividing plane; a fragment obtained by cleaving, as of a diamond. See Parting.
(n.) Division into laminae, like slate, with the lamination not necessarily parallel to the plane of deposition; -- usually produced by pressure.
Example Sentences:
(1) It is possible that the high level of radiolabeled phospholipid found in the plasma membrane arose via the de novo pathway following the cleavage of an acyl group as we have found cytidine diphosphocholine phosphotransferase in the plasma membrane fraction (Wang, P., DeChatelet, L.R., and Waite, M. (1977) Biochim.
(2) Release of nsP4 from P1234 appears to be independent of the other cleavages and occurs primarily immediately after translation.
(3) A broad specificity of LipDH was observed for the glycine cleavage system.
(4) It is the action of this protease that releases the enzyme from the membrane, as shown by the observations that protease inhibitors decreased the amount of solubilization of the enzyme, and the enzyme remaining in the membrane after heating showed much less proteolytic cleavage than that which was released.
(5) One of the proteases obtained was found to catalyse cleavage on the COOH-side of peptide sequences containing consecutive hydrophobic and basic residues.
(6) The results show that in both viral DNAs cleavage occurs at the origin and at one additional site which shows striking sequence homology with the origin region.
(7) These results would suggest that N-terminal acetylation and C-terminal proteolytic cleavage are important post-translational modifications of the forms of Amia beta-endorphin.
(8) We speculate that this cleavage event is catalyzed by either a cryptic potyviral proteinase that requires a host factor or subcellular environment for activation, or possibly a host proteinase.
(9) The relative cleavage frequency at the first glycosidic bond counting from the nonreducing end of the substrate increases with increasing substrate concentration.
(10) An analysis of the triple helical stabilities of these cleavage site regions as reflected by their imino acid contents fails to yield a correlation between reactivity and triple helical stability.
(11) We found that the closer location of Mg2+ to the beta-phosphoryl group than to the alpha- or gamma-phosphoryl group was effective in weakening the P-O bond at which the cleavage of ATP catalyzed by most enzymes takes place.
(12) Subsequently, due to the rotation of the original polar axis in one hemisphere, the third cleavage plane through one half of the egg is transverse to the third cleavage plane through the other half.
(13) It is concluded that in this cell type (i) somatostatin-14 is exclusively generated by dibasic cleavage at the Arg-2-Lys-1 site of the intact precursor with concomitant production of prosomatostatin[1-76], and (ii) no direct interactions between the monobasic and dibasic processing domains occur.
(14) The amount of cleavage products depends on the excess of H2O2 used.
(15) To determine which enzymes are responsible for the processing cleavages of ribosomal RNA transcripts in Escherichia coli, we constructed a mutant strain lacking RNAase III and containing a thermolabile RNAase P. At the nonpermissive temperature, this strain accumulates a novel "19S" RNA species which contains 17S precursor rRNA sequences covalently linked to tRNA sequences transcribed from the ribosomal RNA spacer region between the 16S and the 23S rRNA cistrons.
(16) The cleavage of beta-cyclodextrine by sodium periodate at the seven 2-3 diols of the glucose unit gives rise to the polyaldehyde 1, used to modify alpha-amylase.
(17) The possibility that mammalian DNA topoisomerase II is an intracellular target which mediates drug-induced DNA breaks is supported by the following studies using 4'-(9-acridinylamino)methane-sulfon-m-anisidide (m-AMSA): (a) a single m-AMSA-dependent DNA cleavage activity copurified with calf thymus DNA topoisomerase II activity at all chromatographic steps of the enzyme purification; (b) m-AMSA-induced DNA cleavage by this purified activity resulted in the covalent attachment of protein to the 5'-ends of the DNA via a tyrosyl phosphate bond.
(18) This single substitution was sufficient to abolish all detectable cleavage of the gp160 envelope precursor polypeptide as well as virus infectivity.
(19) Certain RNA molecules can mediate their own cleavage or splicing or act as enzymes to promote reactions on substrate RNA molecules.
(20) The envelope glycoprotein of human immunodeficiency virus consists of two subunits, designated gp120 and gp41, derived from the cleavage of a precursor polypeptide gp160.
Micromere
Definition:
(n.) One of the smaller cells, or blastomeres, resulting from the complete segmentation of a telolecithal ovum.
Example Sentences:
(1) In Strongylocentrotus droebachiensis, a micromere-specific protein of 133 K molecular weight (MW) was identified.
(2) The most extensively studied example is the specification of the mesodermal stem cell in Lymnaea and Patella, which occurs between 5th and 6th cleavage through an interaction between one macromere and a large number of micromeres.
(3) From the early beginning of the 32-cell stage, all four macromeres introdude far into the interior and tough the centrally radiating cells of the first quartet of micromeres.
(4) We suggest that the fibrillar meshwork is needed for macromere elongation toward the micromeres and that the basal lamina-like layer is involved in the determination process itself.
(5) Ilyanassa obsoleta larvae have two calcium carbonate-containing organs, shell and statocyst, which are derived from five micromere cells (2a, 2c, 2d, 3c, 3d).
(6) During the fifth cleavage interval in equally cleaving embryos, one of the vegetal macromeres makes exclusive contacts with the animal micromeres, and this macromere will give rise to the mesodermal precursor cell at the next division, thereby identifying the dorsal quadrant.
(7) Mesomere-mesomeres (which divide equally) and macromere-micromeres (which divide unequally) are compared in terms of their asters (both mitotic and so-called interphase asters), spindle apparatus, and contractile ring.
(8) Caulobothrium longicolle (Linton, 1890) and Phyllobothrium gracile (Weld, 1855) (Cestoda: Tetraphyllidea, Phyllobothriidae) have the same embryonic development with the following characteristic data: --a small number of vitelline cells (2 or 3) pass with the zygote in the ootype;--a non operculate thin egg-shell;--the entire and equal zyhote cleavage following by unequal divisions leading to the formation of four blastomere types (Macromeres, secondary Macromere, Mesomeres and Micromeres);--the differentiation of two syncytial embryonic envelopes during the preoncospheral phase.
(9) To examine competence in this system we have exposed cultured sea urchin micromeres to an inducing medium containing horse serum for various periods of time and have identified a period when micromeres are competent to respond to serum and form spicules.
(10) In Arbacia punctulata, four high molecular weight (HMW) proteins are detected on the surface of isolated micromeres--but not on mesomere-macromere fractions.
(11) Quantitation of immunofluorescence and three-dimensional reconstruction techniques demonstrate that micromere centrosomes differ from macromere centrosomes in two respects: (1) micromere spindle poles contain less centrosomal material than macromere poles, and (2) micromere centrosomes undergo a specific filiform elongation during late anaphase and telophase.
(12) A complementary DNA (cDNA) library was generated from cytoplasmic polyadenylated RNA isolated from differentiated micromere cultures of Strongylocentrotus purpuratus.
(13) Lineages of the first quartet micromeres were followed using Lucifer Yellow dextran as a tracer.
(14) The role of unequal cleavage in echinoid micromere determination was investigated by equalizing the fourth and fifth cleavages with brief surfactant treatment.
(15) We show that in sea urchin embryos, the daughter cells of the small micromeres become part of the coelomic sacs, in contrast to the long-held view that these sacs are purely of macromere origin.
(16) A procedure is described for large-scale isolation of micromeres from 16-cell stage sea urchin embryos.
(17) A method was developed for isolating large quantities of micromeres from the 16-cell stage of the sea urchin, and measurements were made of their ability to incorporate C(14)-L-valine into protein as compared with that of a mixed suspension of micromeres, mesomeres, and macromeres.
(18) Using this method, we fractionated the three different blastomere types of the 16-cell sea urchin embryo, the micromeres, mesomeres, and macromeres, achieving 96, 94, and 96% mean purities, respectively.
(19) Spicule formation of micromere-derived cells was enhanced by anti-FAPS.
(20) pHPSMC mRNA was detected in micromeres in vitro after 48 h of culture, but it was not found in blastomeres immediately after isolation.