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  • 1970-1974  (42)
  • 1971  (42)
  • Life and Medical Sciences  (35)
  • Atomic, Molecular and Optical Physics  (7)
  • 1
    Electronic Resource
    Electronic Resource
    Shifts in nuclear and cytoplasmic nucleic acid content in temperature-synchronized Tetrahymena pyriformis (HSM) (1971)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 77 (1971), S. 93-102 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Nuclei were isolated by exposing temperature synchronized Tetrahymena pyriformis (HSM) to Triton-X-100. Cell division synchrony was induced with a repetitive 12-hour temperature cycle (9.5 hours at 13°, 2.5 hours at 29°). Increase in nucleic acid content was biphasic: primarily during the last two hours of the cold period well in advance of the synchronous burst of division and secondarily in the last hour of the warm period. Nuclear RNA content rises almost two hours ahead of cytoplasmic RNA which shows a maximum 0.5 hour before the onset of the warm period. The DNA content reaches a peak 30 minutes later. On the basis of these shifts there appears to be not net synthesis of nucleic acids during cell division. The changes in RNA/DNA of the isolated macronuclei and micronuclei suggest enhanced RNA turnover, loss to the cytoplasm and enhanced ribonuclease activity prior to cell division. Cytoplasmic RNA also appears to be subject to enzymic degradation.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1040770111
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  • 2
    Electronic Resource
    Electronic Resource
    Sites of protein synthesis in the cells of the zona fasciculata of the young rat adrenal, as shown by electron microscope radioautography (1971)
    New York, NY [u.a.] : Wiley-Blackwell
    American Journal of Anatomy 132 (1971), S. 109-117 
    Details
    ISSN: 0002-9106
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Young rats received 1 mCi of leucine-H3 or tyrosine-H3 intraperitoneally and adrenals were fixed in glutaraldehyde-osmium after 10, 60 and 240 minutes. Epon ultrathin sections were coated with Ilford L4 nuclear emulsion for radioautography. Ten minutes after injection of both tritiated amino acids, labeling indicating the sites of protein synthesis was found principally over the endoplasmic reticulum (∼ 57% of the silver grains) and mitochondria (∼ 32%). Distances of silver grain centers to the nearest interface between these two organelles were plotted; the results seemed to confirm that protein synthesis occurred in the endoplasmic reticulum and mitochondria but was more active in the endoplasmic reticulum. Values remained the same at the other time intervals examined, suggesting the formation of sedentary protein. However, values for the Golgi apparatus were low at ten minutes, fairly high at 60 minutes and low again at 240 minutes, suggesting migration of a small fraction of the newly-formed protein through the Golgi apparatus and subsequent discharge. The possibility is raised of this being an exportable protein.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aja.1001320112
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  • 3
    Electronic Resource
    Electronic Resource
    Growth of the calcareous skeleton during regeneration of spines of the sea urchin, strongylocentrotus purpuratus (stimpson): A light and scanning electron microscopic studyThis work was supported in part by a National Aeronautics and Space Administration Predoctoral Traineeship and represents a portion of a doctoral dissertation submitted to the Department of Zoology, University of California, Los Angeles, California. (1971)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 134 (1971), S. 57-89 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Growth of the skeleton of regenerating spines of the sea urchin, Strongylocentrotus purpuratus, was studied with the light and scanning electron microscopes during the formation of a growth ring or cycle.Growth was initiated about three days after fracture and was linear between 5 and about 40 days after fracture, with a mean rate of 0.16 mm/day. There-after, a decline in growth rate was observed, being attributed to abrasion.The new skeleton first appeared as minute, conical „micro-spines“ on the fractured surface of the spine shaft initiating regeneration of the inner zone of meshwork. Subsequent growth of micro-spines of both the developing inner zone of meshwork, and an outer zone of radiating wedges, formed a conical fenestrated skeleton on the fractured surface of the shaft. Further deposition of micro-spines along the shaft, initially at the level of fracture, formed meshwork which gradually became solidified externally resulting in a new cycle about 60 days after fracture. In contrast, a new cycle was initiated at the milled ring in non-fractured spines during total regeneration on bare tubercles, demonstrating that growth of spines also takes place in the absence of fracture.Experiments conducted in vitro demonstrate that spine regeneration is not a polar phenomenon.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051340105
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  • 4
    Electronic Resource
    Electronic Resource
    The histology of the first batch of eggs and their associated tissues in the ovariole of Dysdercus fasciatus signoret (heteroptera: Pyrrhocoridae) as seen with the light microscope (1971)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 134 (1971), S. 105-129 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: In the telotrophic ovarioles of Dysdercus fasciatus, mononucleate, binucleate and multinucleate trophocytes are seen in the germarium. Cellular breakdown of the multinucleate cells is seen in the posterior part of this tissue. The nutritive cords, which are continuous with the trophic core at the one end and the oocytes of the vitellarium at the other, contain material of fibrous appearance which continues into the trophic core. The ovariole is enclosed in two sheaths throughout its length. Prefollicular tissue in the germarium appears to give rise to the follicle cells. Mitosis is common in this zone. Oocytes are at first surrounded by a multilayered epithelium. This is later reduced progressively to one layer. This one layered follicular epithelium is at first columnar but then changes to cuboidal mononucleate, cuboidal binucleate and finally to a squamous binucleate condition This epithelium thus seems to accommodate the increased volume of the oocyte by growth and a change of shape. The oocyte grows fastest at those times when it is surrounded by cuboidal and squamous epithelial cells.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051340107
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  • 5
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    Electronic Resource
    The fine structure of the pigment epithelium and photoreceptor cells of the newt, Triturus viridescens dorsalis (Rafinesque)This work was supported by grants from the Medical Research Council of Canada, the E. A. Baker Foundation for the Prevention of Blindness and Fight For Sight, Inc. (1971)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 135 (1971), S. 389-431 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The morphology of the retinal pigment epithelium and photoreceptor cells has been studied in the common newt Triturus viridescens dorsalis by light, conventional transmission and scanning electron microscopy.The pigment epithelium is formed by a single layer of low rectangular cells, separated by a multilayered membrane (Bruch's membrane) from the vessels of the choriocapillaris. The scleral border of the pigment epithelium is highly infolded and each epithelial cell contains smooth endoplasmic reticulum, myeloid bodies, mitochondria, lysosomes, phagosomes and an oval nucleus. Inner, pigment laden, epithelial processes surround the photoreceptor outer and inner segments.The three retinal photoreceptor types, rods, single cones and double cones, differ in both external and internal appearance. The newt, rod, outer segments appear denser than the cones in both light and electron micrographs, due to a greater number of rod lamellae per unit distance of outer segment and to the presence of electron dense intralamellar bands. The rod outer segments possess deep incisures in the lamellae while the cone lamellae lack incisures. Both rod and cone outer segments are supported by a peripheral array of dendritic processes containing longitudinal filaments which originate in the inner segment. The inner segment mitochondria, forming the rod ellipsoid, arelong and narrow while those in the cone are spherical to oval in shape. The inner segments of all three receptor cell types also contain a glycogen-filled paraboloid and a myoid region, just outside the nucleus, rich in both rough and smooth endoplasmic reticulum. The elongate, cylindrical nuclei differ in density. The rod nuclei are denser than those of the cones, contain clumped chromatin and usually extend further vitreally. Similarly, the cytoplasm of the rod synaptic terminal is denser than its cone counterpart and contains synaptic vesicles almost twice as large as those of the cones. Photoreceptor synapses in rods and cones are established by both superficial and invaginated contacts with bipolar or horizontal cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051350402
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  • 6
    Electronic Resource
    Electronic Resource
    The endodermal nerve net of Scyphozoa (1971)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 133 (1971), S. 105-123 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The endodermal nerve nets of the scyphozoan jellyfish Phacellophora camtschatica and Cyanea capillata were stained with methylene blue. Small animals (3-7.5 cm in diameter) stained easily. The endodermal nerve net of both species is a synaptic net consisting of bipolar and some few tripolar nerve cells with unbranched neurites. The neurites terminate on other neurites. Very few free nerve endings were observed. The neurites have a diameter of 1/4-1/2 μ and there is no indication of the presence of neurites too fine to be followed in the light microscope.The gross appearance of the net changes with the size of the medusa. Staining 15-53 cm diameter animals showed that the nerve cells increase in size with the size of the animals, that the density of the nerve net decreases.The endodermal nerve net is very similar to our interpretation of the Diffuse Nerve Net of the ectoderm but without the typical primary sense cells. In both cases the appearance of branching neurites is interpreted as an artifact caused by neurites terminating on other neurites.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051330106
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  • 7
    Electronic Resource
    Electronic Resource
    The structure and development of the hairpencil glands in males of the queen butterfly, Danaus gilippus berenice (1971)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 134 (1971), S. 215-241 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Queen butterflies do not mate until the male has brushed the tufts of his scented, abdominal “hairpencils„ over the female's head and antennae. The trichogen cells located at the base of each hairpencil are secretory. Presumably, these cells produce the sex pheromone necessary for mating. The liquid secretion must move from a central, microvillus-lined vesicle through the cuticle of the hairs to coat numerous, free, cuticular „dust“ particles which adhere to the hairs' surface. The dust carries the secretion to or near the female's antennae. In the pupal stage the dust particles develop as outpocketings of the hair epicuticle. An amorphous matrix, probably protein epicuticle, is deposited in the outpocketings between the cuticulin layer and plasma membrane of the hair. Before the butterfly emerges from the pupa the matrix becomes enclosed by cuticulin, and the particles pinch off from the hair.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051340206
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  • 8
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    Attachment and metamorphosis of the cheilo-ctenostome bryozoan bugula neritina (linné)This investigation was supported by research grant GB-18802 from the National Science Foundation and Biomedical Sciences Support grant FR-07012-02 from the National Institutes of Health. Laboratory space at SCMBL was provided through the generosity of the Arthur Vining Davis Foundation. The authors are indebted to Dr. B. C. Abbott for use of facilities at the Allan Hancock Foundation, Dr. R. R. Given for collection of specimens, and Drs. K. Fauchald, D. F. Soule, and J. D. Soule for critical evaluation of the manuscript.Contribution 1 from the Santa Catalina Marine Biological Laboratory. (1971)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 134 (1971), S. 351-382 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The structure, attachment and subsequent metamorphosis of larvae of the marine bryozoan Bugula neritina were studied by light and electron microscopy.Two points of larval anatomy are of special significance to proper interpretation of the metamorphosis: 1Two cytologically similar blastemal tissues, each laden with free ribosomes, occur as parts of the apical organ complex. The upper blastema directly contacts the larval surface, forming the non-ciliated rows of the apical organ. The lower blastema is internal and is oral to and contiguous with the upper blastema.2The epidermal tissues of the larva are joined in the following sequence, beginning at the aboral pole: a. apical organ complex; b. apical-connecting cell; c. infolded pallial sinus epithelium; d. vesicular-connecting cell; e. aboral vesicular epithelium; f. corona; g. oral vesicular epithelium; and i., j., and k. internal sac neck, wall and roof regions.The initial stages of metamorphosis involve a complex sequence of morphogenetic movements, including: 1eversion of the internal sac, permanently attaching the larva to the substrate;2inrolling of the aboral vesicular epithelium, corona, oral vesicular and ciliated epithelia, and neck region of the internal sac into the larval interior; concomitantly the pallial sinus epithelium evaginates;3loss of connection between the invaginated tissues and the surface;4fusion of the pallial sinus epithelium with the wall region of the internal sac, maintaining the integrity of the body surface;5retraction of the apical organ complex and invagination of the pallial sinus epithelium with the simultaneous elevation of the internal sac wall region to the aboral pole.At the conclusion of these events the preancestrular surface is covered by the wall and roof regions of the internal sac. Cells of the wall region form the epidermis of the body wall except for the attachment disc and secrete a cuticular exoskeleton that is secondarily calcified; the attachment disc is formed by the roof region of the internal sac.Internally, the ectodermal upper blastema differentiates into the lophophore and digestive tract of the ancestrular polypide, while the lower blastema forms the lining of the lophophoral coelom and the splanchnic (but not the somatic) lining of the visceral coelom. The visceral somatic peritoneum is formed from cells that may originate from the mesodermally derived pigmented cells of the larva to which they are similar in pigmentation and cytology. Such a composite derivation of a coelomic lining has not been described previously.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051340307
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  • 9
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    Electronic Resource
    The biosynthesis of protamine during spermatogenesis of the mouse: Extraction, partial characterization, and site of synthesis (1971)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 78 (1971), S. 13-24 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: A highly basic, testis-specific, chromosomal protein (MP) can be extracted with acid from testis cells of the mouse, but not from mature spermatozoa. A similar protein (MP') can be isolated from spermatozoa if they are first disrupted with β-mercaptoethanol and urea. The two proteins (MP and MP') are identical as characterized by polyacrylamide gel electrophoresis, Bio-Gel P-10 chromatography, amino-acid analysis and equilibrium ultracentrifugation. They are presumably mouse protamine. Both measurements of the sedimentation velocities of testis cells which synthesize mouse protamine and of the activity of spermatozoa after a pulse label with radioactive arginine show that protamine is synthesized 19 days after the last meiotic S-phase, that is, at an advanced stage of spermiogenesis.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1040780104
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  • 10
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    Electronic Resource
    Stimulation by serum of multiplication of stationary chicken cells (1971)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 78 (1971), S. 161-170 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: When serum was added to cultures of stationary chicken fibroblasts, there was an increase in the percentage of cells synthesizing DNA after a delay of about five hours. If the serum was removed before DNA synthesis began, some cells were still found to start DNA synthesis and to enter mitosis. The delay between the time of addition of serum and the start of DNA synthesis was not affected by the type of serum, the concentration of serum, nor the means of preparing the stationary cells. However, all of these factors affected the proportion of cells stimulated by serum.If two pulses of serum were given immediately following each other, their effects were synergistic. If there were twelve hours between them, there was no effect of the first pulse. These results were summarized in a new model of the cell cycle which subdivided the G1 phase into Gla, b, and c.The effects of serum were seen in a balanced salt solution, and were sensitive to several metabolic inhibitors.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1040780202
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