(n.) A fishlike creature (Amphioxus lanceolatus), two or three inches long, found in temperature seas; -- also called the lancelet. Its body is pointed at both ends. It is the lowest and most generalized of the vertebrates, having neither brain, skull, vertebrae, nor red blood. It forms the type of the group Acrania, Leptocardia, etc.
Example Sentences:
(1) In situ, CaVP forms a high affinity Ca2+-dependent complex with an Mr 36,000 protein present in muscle extracts of amphioxus.
(2) Amphioxus CaVP does not substitute for calmodulin in a specific enzyme assay nor for troponin C in restoring Ca2+ sensitivity to skinned muscle fibers.
(3) Joseph cells, assumed to be photoreceptive organs in amphioxus, were studied by electron microscopy as well as by a histofluorescence technique.
(4) Like proinsulin, amphioxus proILP contains a C-peptide, which is flanked by paired basic residues and is probably removed by proteolysis.
(5) Sequence comparisons show that the amphioxus ILP A and B domains are equally homologous to those of human insulin and IGF-I and -II.
(6) The activities of the creatine-synthesizing enzymes, arginine-glycine transamidinase and guanidinoacetate methylpherase, were not detected in the hagfish or in any of the invertebrates, including those in which creatine was found, with the exception that transamidinase activities were detected in the amphioxus and salt water clam; however, these activities are considered to be artifacts for reasons mentioned in the text.
(7) None of the five epitopes was expressed on amphioxus, nematode, or Dictyostelium MHC.
(8) Crystals of a sarcoplasmic Ca(2+)-binding protein from the protochordate amphioxus have been grown from solutions of ammonium sulfate.
(9) In the Amphioxus genome repetitive and non-repetitive elements are predominantly arranged in a short period interspersion pattern.
(10) A new Ca2+-binding protein, called CaVP, has been detected in muscle of the cephalochordate amphioxus and purified to electrophoretic homogeneity.
(11) Based on these results and the exon-intron organization of the amphioxus ILP gene, we propose that IGF emerged at a very early stage in vertebrate evolution from an ancestral insulin-type gene.
(12) To gain an insight into the molecular changes that accompanied the evolution of vertebrate embryology, and into the relationship between the amphioxus and vertebrate body plans, we have undertaken the first molecular level investigation of amphioxus embryonic development.
(13) The presence of S-antigen in distant species (vertebrates, Amphioxus, nemerteans, annelids, molluscs) indicates a high phylogenetic stability and suggests an important role for this protein in photoreceptor function.
(14) The protochordate amphioxus (Branchiostoma lanceolatum) contains different isoforms of sarcoplasmic, high-affinity Ca2(+)-binding proteins (SCP).
(15) The nervous system of amphioxus tells us little, or nothing, about the ancestral vertebrate system.
(16) It is concluded that two independent mechanisms of ionic permeability increase occur in the membrane of amphioxus muscle cell, one to Na and the other to Ca.
(17) This was also the case with skeletal muscle of prochordate, Amphioxus.
(18) The present study demonstrates for the first time by RIA that LH-RH is present in the heads as well as the bodies of the amphioxuses of both sexes.
(19) Spinal cords of 15 species representing six classes of vertebrates and the protochordate amphioxus were examined with histochemical methods for esterase, ATPase, LDH, PAS, and PAS-phosphorylase.
(20) Its relative abundance in amphioxus muscle indicates that CaVP must underlie an important new limb of Ca2+ regulation in this particular muscle.
Branchiostoma
Definition:
(n.) The lancelet. See Amphioxus.
Example Sentences:
(1) The segmented trunk muscle (myotome muscle) of the lancelet (Branchiostoma lanceolatum), a pre-vertebrate chordate, was studied in order to gain information regarding the evolution of excitation-contraction (EC) coupling.
(2) RIA alone was performed in extracts from branchiostoma and cricket.
(3) Eight individual proteins--calcineurin B from Bos, troponin C from Astacus, calcium vector protein from Branchiostoma, caltractin from Chlamydomonas, cell-division-cycle 31 gene product from Saccharomyces, 10-kd calcium-binding protein from Tetrahymena, LPS1 eight-domain protein from Lytechinus, and calcium-binding protein from Streptomyces--are tentatively identified as unique; that is, each may be the sole representative of another subfamily.
(4) A lectin was isolated from an extract of Branchiostoma lanceolatum by affinity chromatography using an asialo-A-peptone-cellulose column.
(5) We conclude that the Branchiostoma myotome cells have only one Ca2+ channel system.
(6) The investigation was carried out with representatives of all vertebrate classes as well as with the protochordates Branchiostoma lanceolatum and Ciona intestinalis.
(7) Mucus from Metridium senile, Ophiocomina nigra and Branchiostoma lanceolatum yielded positive results and was investigated further.
(8) We have determined the complete sequences of 5S rRNAs from a lamprey (Lampetra reissneri), a lancelet (Branchiostoma belcheri), silkworms (Philosamia cynthia ricini, Bombyx mori, Antheraea pernyi), and a silkworm hybrid (artificially fertilized hybrid species of Philosamia cynthia ricini male x Bombyx mori female), as well as those of cotton seeds (Gossypium hirsutum L.).
(9) The preotic mesomeres of Cyclostomata are homologous to II--IV mesomeres of Branchiostoma lanceolata.
(10) By using the whole-cell patch clamp method Ca2+ and Ba2+ currents were measured in the extremely thin twitch muscle cells of the protochordate Branchiostoma lanceolatum whose Ca2+ channels are likely to resemble the evolutionary ancestors of those found in vertebrate skeletal muscle.
(11) The protochordate amphioxus (Branchiostoma lanceolatum) contains different isoforms of sarcoplasmic, high-affinity Ca2(+)-binding proteins (SCP).
(12) The physical and chemical properties of a hemagglutinin from whole-body homogenates of the cephalochordate, Branchiostoma lanceolatum, are described.
(13) We report the molecular cloning of a full-length cDNA encoding a non-neuronal cytoplasmic intermediate filament (IF) protein of the cephalochordate Branchiostoma lanceolatum.
(14) In adult Branchiostoma, the coelomic epithelium which coats the contractile blood vessels had been found to differentiate into muscle cells that remain uncoated on the side facing the coelomic cavity (Franz 1933; Joseph 1914, 1928).
(15) The anterior cephalic cavity and the premandibular segment of the elasmobranchia are homologous to I and II segments of Branchiostoma lanceolata.
(16) In line with the absence of protein sequence similarity of the tail domain, the Branchiostoma gene does not possess the introns interrupting this region in type III genes of vertebrates.
(17) In a limited survey, the lower chordate Branchiostoma as well as the invertebrates Arenicola, Lumbricus, Ascaris, and Helix pomatia revealed a positive reaction primarily on epithelia and on nerves, whereas certain other invertebrates appeared negative.
(18) To investigate this issue, we recently cloned a cDNA encoding an insulin-like peptide (ILP) from a primitive chordate species, amphioxus (Branchiostoma californiensis).
(19) This paper attempts to define some of the features of the motor system of early vertebrates based on studies of the motor systems in anamniotes and in Branchiostoma.
(20) Excitation-contraction coupling was studied in myotomal muscles of amphioxus, Branchiostoma californiense.2.