Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “TURBELLARIA”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 37 records · Page 2Linked to original sources
PubMed1981

The nervous system of Microstomum lineare (Turbellaria, Macrostomida). II. The ultrastructure of synapses and neurosecretory release sites.

The ultrastructure of release sites of neurochemical messenger substances in the microturbellarian Microstomum lineare was examined. Aminergic neurites form conventional synapses and synapse-like structures (SLS). Variants of true synapses include: "single" synapses with symmetric pre- and postsynaptic densities, "shared" synapses, i.e., contacts between 1 pre- and 2 postsynaptic fibres, en passant synapses between parallel axonal membranes, and synapses without thickenings having only clustered vesicles in the presynaptic terminal. SLS on a nerve cell soma or facing an intercellular stromal channel near muscles are described. Peptidergic neurites containing large granular vesicles (LGV) from synaptoids and signs of putative neurosecretory release. Synaptoids between neurites and between neurite and muscle have lucent vacuoles (about 100 nm) and dense material at the contact site. In en passage synaptoids dense-core vesicles are embedded in electron-dense material at the contact site. Putative signs of release of neurosecretory material other than "typical" exocytosis have been observed.

Amines↗
PubMed1978

The epidermis and sensory organs of Dugesia tigrina (Turbellaria: Tricladida). A scanning electron microscope study.

The epidermis of D. tigrina was examined using the scanning electron microscope. Both dorsal and ventral surfaces are extremely irregular in contour, as well as being permeated by large numbers of pores. Cilia are restricted to the ventral surface, the auricles and that part of the dorsum adjacent to the auricles. Club-shaped receptors, as well as cilia, were seen in the auricles. The epidermis anteriad to the eyespots is indistinguishable from that covering the remainder of the dorsal surface. Light rays could not enter the eyespot through this rough epidermal surface without becoming diffracted in an irregular fashion. It was therefore concluded that visual image perception is not a function of the planarian eyespot.

Animals↗
PubMed1985

Meiosis in Mesostoma ehrenbergii ehrenbergii (Turbellaria, Rhabdocoela). III. Univalent chromosome segregation during the first meiotic division in spermatocytes.

At metaphase I of meiosis in spermatocytes of Mesostoma ehrenbergii ehrenbergii [2n = 10] three bivalents and four univalents form. The same two chromosome pairs always form the univalents. Analysis of metaphase I, anaphase I and metaphase II configurations in fixed testis material suggested that the distribution of the four univalents is not a random process but the correct segregation of one member of each pair to each pole is actively achieved before the end of metaphase I. In live preparations of testis material univalents were observed to move between the poles of metaphase I cells, eventually reaching the correct segregation. All cells observed to enter anaphase I had the correct segregation of univalents. It is proposed that the univalent movement during metaphase I is directed towards obtaining the correct segregation of univalents before the cells enter anaphase.

Animals↗
PubMed1990

Demonstration by immunocytochemical staining of a somatostatin-28-(1-14)-like peptide in planarians (Plathyhelminthes Turbellaria Tricladida).

A specific polyclonal antiserum directed against the somatostatin-28(1-14) of vertebrates was applied to sections of the planarians Dugesia lugubris and Dendrocoelum lacteum. This made it possible to reveal nerve cells and processes specifically both in cerebral ganglia and in ventral nerve cords. The phylogenetic importance of this demonstration is pointed out.

Animals↗
PubMed2004

Immunoenzymatic visualization of tetrodotoxin (TTX) in Cephalothrix species (Nemertea: Anopla: Palaeonemertea: Cephalotrichidae) and Planocera reticulata (Platyhelminthes: Turbellaria: Polycladida: Planoceridae).

Tetrodotoxin (TTX) was localized as brown color in different tissues of an undescribed species of the nemertean genus Cephalothrix (phylum Nemertea) and a turbellarian Planocera reticulata (phylum Platyhelminthes) on light microscopy by means of a monoclonal anti-TTX antibody. In the Cephalothrix sp., TTX was recognized in the vesicles apically arranged in the bacillary cells in the epidermis, basal lamina, the granular cells in the proboscis epithelium, rhynchocoel epithelium, and the vesicles in the basal portion of the intestinal wall near the blood vessels and rhynchocoel. The excretory system and the ovum also showed positive reaction of TTX antigen-antibody. On the other hand, the hermaphrodite flatworm P. reticulata exhibited TTX antigen-antibody complex only in their ovum. To our knowledge, this is the first experimental effort on micro-distribution of TTX in invertebrates.

Animals↗
PubMed1969

The "9+1" pattern of microtubules in spermatozoa of Mesostoma (Platyhelminthes, Turbellaria).

The living spermatozoa of the flatworm Mesostoma georgianum have a sperm body about 100 mu long and 0.5 mu wide, and two motile free flagella, ca. 200 mu long. In sections examined with the electron microscope, these flagella have the usual nine pairs of peripheral doublet microtubules and have a single central core unit which is connected to the A members of the doublets by spokelike structures. There are also short connections between the doublets and the flagellar membrane. In material negatively stained with phosphotungstic acid, the doublet microtubules seem to have very different elastic properties than the core; they tend to fall on the copper grids in coils of rather uniform diameter (2-4 mu), while the core is much more rigid and is often found extending alone, along a relatively straight course, for very long distances (up to 73 mu). After negative staining, the core has a striking appearance with a dense center around which are wound two hollow structures in a double helix of 45 degrees pitch. The center-to-center distance of each gyre is approximately 650 A, and the hollow structures are ca. 180 A in diameter.

Animals↗
PubMedDate not supplied

A method for the preparation of high-molecular-weight DNA from marine and freshwater triclads (Platyhelminthes, Turbellaria).

Although the last decade has seen much activity devoted to the phylogeny of the Platyhelminthes, such activity has relied in the main on traditional anatomical, ultrastructural, and developmental data. Extension of these studies to the molecular level has been impeded by the lack of a reliable method for the isolation of DNA from these organisms, especially marine triclads whose DNA is particularly difficult to isolate using methods currently used with other eukaryotic or prokaryotic organisms. We report here the details of a method that results in the rapid isolation of relatively pure DNA in good yields from small amounts of material. The method involves the treatment of the animals with high concentrations of NaDodSO4 followed by phenol extraction, resulting in a product that is an excellent substrate for restriction endonuclease digestion and Southern blotting.

Animals↗