Origin of the golgi complex in germ cells in the developing ovary of the bat

Summary Dense lamellar bodies (DLB) were noted in immature cells in the developing ovary of the free-tailed bat. The DLB appear to be formed in the nucleus. They pass through the nuclear membrane into the cytoplasm. There they give rise to parallel stacks of flattened cisternae which are representative of typical dictyosomes. During the first meiotic prophase the dictyosomes aggregate to form the Golgi complex.This study was supported in part by a research grant from U.S.P.H.S. (GRS 5 SO1 RR 05704-01).The authors wish to acknowledge the technical assistance of Mrs. Edna Burgess.     

Germ cell degeneration and intercellular bridges in the human fetal ovary

Summary Intercellular bridges between developing germ cells were observed in human fetal ovaries at 10 to 20 weeks gestation. Bridges were frequently found between cells in early stages of degeneration, with similar regressive changes being present in the conjoined cells. In advanced stages of cellular degeneration, bridges were less frequently found and were generally distorted and partially disrupted. Similarity in appearance of adjacent degenerating cells was common, even in late stages of degeneration. These observations suggest that cellular interconnection may be responsible for synchronous degeneration of germ cells during oogenesis.The author thanks Mrs. Lucy A. Conner for her valuable technical assistance. This research was supported by U.S.P.H.S. grant HD-05727.     

Statice Virus Y - a Virus related to Bean Yellow Mosaic and Clover Yellow Vein Viruses

The authors are greatly indebted to the Deutsche Forschungsgemeinschaft for financial support, to Miss B. M urthlm , Mrs. U. H erzberg , Mrs. B. H ane and Miss P. R ahse for reliable technical assistance and to Dr. M. H ollings , Dr. R. O. H ampton and Mr. D. Z. M aat for gifts of antisera.     

Directionally selective motion detecting units in the optic lobe of the honeybee

Summary We have found four classes of neurons in the honeybee optic lobe. These neurons respond to changes in light intensity and selectively to movement of objects within the entire acceptance angle of a compound eye. We suggest that these neurons are part of the neural system that controls flight, for example the optomotor response. Properties of these units are described in this paper. To our knowledge this is the first report of recording from interneurons of the honeybee.We thank Mrs. B. Hsei and Mrs. D. Hodgetts for technical assistance. Bees to establish the wild-type colony were given by Dr. P. Wells, Occidental College; bees to establish the white-eyed mutant colony were given by Dr. H. Laidlaw, University of California at Davis, California.This research was supported by National Institutes of Health, U.S.P.H.S. Grant NB03627 to Dr. G. D. McCann (CIT), and A.F.O.S.R. Grant 70-1869 to LGB.One of us (WK) is indebted to the Commitee on International Exchange of Persons, Washington D.C., for making available a Fulbright Travel Grant. WK also thanks Dr. G. D. McCann for the invitation to the California Institute of Technology.     

Ultrastructural study of the regressing prothoracic glands of blattarian insects

Summary The prothoracic glands, source of the molting hormone ecdysone, regress within a few days after the final molt, a process which was analyzed with electron microscopic methods in the cockroaches Leucophaea and Blaberus. This strictly timed event is accompanied by drastic alterations in cellular fine structure. Early signs of breakdown appear in groups of nuclei whose substance becomes segregated into patches of contrasting electron density characteristic of pyknosis.The most conspicuous change in the cytoplasm of parenchymal cells concerns the appearance of large, heterogeneous inclusion bodies in which various cellular elements become segregated. These compartments seem to represent autophagic vacuoles within which the gradual degradation of much of their contents takes place, presumably under the influence of lysosomal enzymes. Undigested swirls of membranous character may remain sequestered within these packets for some time.At advanced stages of cellular atrophy, plasma membranes and nuclear envelopes have gradually disappeared, and masses of protoplasm undergoing autolysis become invaded by a greater number of hemocytes than are present in nymphal glands. These phagocytic elements appear to engulf debris of parenchymal cells as well as some degenerating connective tissue elements. After the completion of the regressive process, the axial band of musculature characteristic of the nymphal gland persists on its own. Whether or not some parenchymal cells (or possibly their precursors) capable of reactivation persist in the proximity of this muscle is unknown.The resorption of the prothoracic gland in the newly emerged insect is the result of physiological autolysis and seems to be aided by the activity of phagocytic hemocytes.Dedicated to Professor W. Bargmann on his 60th birthday in friendship and admiration.This study was supported by Research Grants AM-03984, NB-02145 and NB-05219 from the U.S.P.H.S.I wish to express my thanks to Mrs. S. Wurzelmann, Mrs. C. Jones, Mrs. C. Grubman, and Mr. S. Brown for their excellent technical assistance.     

The blood group U antigen is not located on glycophorin B

Erythrocytes from twelve individuals with the S-s-U- phenotype and from ten with the S-S-U+ phenotype were analyzed and compared to control cells with S+/s+U+ determinants. No red cell abnormality was detected in S-s-U+ or S-s-U- carriers. Sialic acid content was similar (P greater than 0.05) for S-s-U+ and S-s-U- erythrocytes (74.6 +/- 7.14 and 71.4 +/- 8.53 nmol/10(9) red blood cells, respectively) but significantly less (P less than 0.001) than controls with 89.5 +/- 11.4 nmol/10(9) red blood cells, n = 16. Fluorographs of SDS-polyacrylamide gels showed no glycophorin B in membranes from S-s-U+ and S-s-U- erythrocytes labeled with NaB3H4. Glycophorins were extracted from red cell membranes in chloroform/methanol, labeled with 125I and analyzed by SDS-polyacrylamide gel electrophoresis. Periodic acid Schiff stain and autoradiographs of these gels also showed absence of glycophorin B in both S-s-U+ and S-s-U- cells. These findings suggested that the U antigen is not located on glycophorin B. This hypothesis was tested by determining blood group antigenicity on red cell membranes and on extracted sialoglycoproteins by the hemagglutination inhibition technique. Although U and S/s activities were detected in control red cell membranes, extracted glycoproteins demonstrated S/s activity but no U activity. Together the data indicate that both S-s-U+ and S-s-U- erythrocytes lack glycophorin B and that the U antigen is not located on glycophorin B. This deletion does not seem to affect the structure-function of the red cell.     

The Kurloff cell

Summary Kurloff cells belong to the group of macrophages as far as ultrastructure, adhesiveness and identification with Kupffer cells (in the case of the liver) are concerned. A characteristic group of features makes it easy to recognize them: PAS reaction, cyanol-blue staining, presence of myelin figures in electron microscopy and attachment to glass-slides.Kurloff cells are thymic and blood cells. They are observed in small numbers in the circulating blood and, in large quantities, in spleen (red pulp), liver (hepatic sinusoids) and lung (septal capillaries). They are absent from lymphatic nodules and from diffuse lymphatic tissues.Morphological and experimental studies indicate that, in spite of some equivocal similarities, Kurloff cells are distinguishable by many criteria from erythrophagocytic cells and from protein-secreting blood cells.The authors wish to express their appreciation to all those who have so kindly assisted in the preparation of this paper: Professor P. Galle of C.H.U. Henri-Mondor, Head Physician A. Michaud of G.E.R.S. of Toulon-Naval, Mr. J. P. Thiery of the Centre de Recherches d'Ivry, Mrs. E. Lehman, A. Thouin and P. Boussin of the Université de Caen. Melle A. Deshayes patiently typed the text     

An autoradiographic and electron microscopic study of retino-hypothalamic connections

Summary Retino-hypothalamic connections have been studied autoradiographically in the rat, guinea pig, rabbit, cat and monkey following the intravitreal injection of ³H-leucine or ³H-proline, and electron microscopically following unilateral eye removal in the guinea pig and monkey. In each of the species examined evidence has been found for a direct projection from the retina to the suprachiasmatic nucleus, but to no other region of the hypothalamus. The projection to the suprachiasmatic nucleus is always bilateral (even in the albino guinea pig, in which all other components of the retinal projection are crossed) but from grain counts in our autoradiographs it appears that the input to the contralateral nucleus is about twice as heavy as that on the ipsilateral side. Most of the retinal fibers appear to terminate within the ventral part of the nucleus where they form asymmetric synapses either upon small dendritic branches or dendritic spines. The possible role of this retinal projection to the suprachiasmatic nucleus in mediating a variety of light-induced neuroendocrine responses is discussed.This work was supported in part by Grants 5 PO1 EY-00491 and 5 RO1 EY-00599 from the National Eye Institute, by U.S.P.H.S. Grant HD 02274, and by Regional Primate Center Grant RR 00166.We should like to thank Mrs. Lue-Vurn Bell, Mrs. Bente Noble, Mrs. Gay Anderson and Mrs. Ludelle Moe for their excellent technical assistance, and Miss Lynn Rogers for her help with the illustrations.     

Cytochemical and ultrastructural studies of ribonucleoprotein containing structures in oocytes of Acheta domesticus

Summary Two distinct types of ribonucleoprotein containing structures are found in oocytes of the house cricket, Acheta domesticus, a large secondary or accessory nucleolus and many small primary nucleoli. The secondary nucleolus increases in size during oocyte development and is similar in appearance to the nucleolus of somatic cells. The primary nucleoli are intimately associated with a large, extrachromosomal DNA containing body. The DNA body is no longer visible in nuclei of late diplotene stage cells when the primary nucleoli are dispersed within the nucleoplasm. Both types of nucleoli contain cytochemically detectable RNA and acid protein, little or no DNA and basic protein, and particulate structures similar to but smaller than cytoplasmic ribosomes.The authors acknowledge the technical assistance of Miss Celeste Malinoski and Mrs. Marcia Andrews. This work was supported by a U.S.P.H.S. grant, number GM-16440-01 and grants number L-16 and J-1 from the Health Research Services Foundation.     

Distribution of monoamine oxidase in the hippocampal region of the guinea pig

Summary 1. The distribution of monoamine oxidase (MAO) within the dentate area, a part of the hippocampal region, has been described for the adult guinea pig.2. The histochemical demonstration of the enzyme was done essentially according to the tryptamine-tetrazolium method of Glenner et al., and the staining reactivity was controlled by complete inhibition with iproniazide.3. Most of the MAO in the dentate area was present in a stratified pattern. Within the molecular layer, a supragranular third reacted heavily, while a more weakly staining superficial layer could be distinguished from an intermediate, still paler lamina. The granular cell bodies were unstained. In the hilus, five layers showing alternating stronger and weaker activity were observed. The distribution of the MAO staining was compared with conventional anatomical subdivision of the dentate region.4. The guinea pig dentate area appears to have a greater amount and more stratified distribution of MAO than the comparable region previously described in the rat.I am indebted to Mrs. E. Kjær Hansen, Mrs. L. Knudsen, Mr. A. Meier, Mr. Th. Nielsen, Mrs. K. Sørensen, and Miss M. Sørensen for skillful technical assistance. This study was supported in part by U.S.P.H.S. Grant NS 07998.     

Large-scale partial purification of phytochrome from green leaves of Avena sativa L.

Phytochrome from 10 or 11-d-old oat (Avena sativa L. cv. Garry) leaves, which were harvested just prior to sunset from plants grown in a greenhouse in the absence of supplemental illumination, was purified an estimated 250-fold by sequential poly(ethylenimine) and ammonium-sulfate fractionations, followed by linear-gradient hydroxyapatite chromatography. Compared to earlier protocols, the one presented here is substantially more rapid, provides improved yield and purity, can be used with larger quantities of tissue, and eliminates an apparently immunodominant contaminant with a molecular mass of about 115 kDa (kilodalton). Phytochrome obtained by this procedure has an apparent monomer size of 123 kDa as evaluated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and is estimated to be 0.6% pure. This purity permitted spectral analysis at wavelengths below 500 nm, in which region phytochromes from green and etiolated oat shoots do not differ markedly, as they do at longer wavelengths.Abbreviations Da Dalton - HA hydroxyapatite - Pfr, Pr farredand red-absorbing form of phytochrome, respectively - SDS sodium dodecyl sulfate This research was supported by the U.S. Department of Energy (contract DE-AC-09-81SR10925 to L.H.P.). The excellent technical assistance of Mrs. Donna Tucker and Mrs. Danielle Neal is gratefully acknowledged.     

Golgi potassium-dichromate silver-nitrate impregnation

Summary Golgi preparations were made by consecutive treatment of formalin-fixed brain and liver with potassium dichromate and silver nitrate. Impregnated tissue dissected from thin slices of the blocks were studied by X-ray powder diffraction methods, in a diffractometer and a Guinier camera. Such tissue proved to contain crystalline silver chromate, Ag₂CrO₄, both while still in the silver nitrate solution and after dehydration in ethanol and clearing in xylene and xylene-Dammar resin. No other compounds containing chromium or silver were detectable. Formalin-fixed tissue merely treated with silver nitrate contained silver chloride, but in impregnated tissue the amount was too scarce to be visible. Hence, silver chloride was no integral part of the Golgi precipitate.A number of mostly ethereal oils traditionally used for clearing histological sections, did not cause the appearance of metallic silver in detectable amount in the Golgi preparations. However, after treatment with clove oil and creosote metallic silver was detected in the tissue.This study was supported by U.S. P.H. S. Grant NS 07998. This aid is gratefully acknowledged.We are indebted to Miss I. Madsen and Mrs. K. Sörensen for technical assistance.     

The ultrastructure of monkey eccrine sweat glands

Summary The ultrastructure of monkey eccrine sweat glands is described. The secretory portion of the sweat gland is discussed in detail. The morphological differences in the secretory coil using three different fixatives and fixative combinations are emphasized. The secretory product of dark cells is seen to have three distinct appearances depending upon the fixative used. The biochemical significance of the latter finding is discussed. The appearance of clear cell cytoplasmic processes is described using the different fixatives. The similarity of adjacent clear cell processes to those of avian salt glands is pointed out and discussed. Evidence is presented to indicate that dark cells arise from clear cells via an intermediate cell type. The appearance of the clear cell plasma membrane is described and the necessity for the use of the general term multilaminar plasma membrane is discussed.Supported by U.S.P.H.S. grant 5 T 1-GM-29 F-04 AS. The author would like to express his gratitude to the Lederle Laboratories and in particular to Dr.James Vickers for providing the tissue. Sincere thanks is given to Mrs.Dagmar Graham and Mrs.Ditza Springer for technical assistance and also to MissMary Lorenc for preparation of the diagram. In addition, I would like to thank Dr.J. A. G. Rhodin for his criticism and advice.     

A specialized trophospongium in large neurons of Leptodora (Crustacea)

Summary A specialized type of trophospongium has been described in large nerve cells of the cerebral ganglion of the planktonic crustacean Leptodora kindtii. It consists of three parts (Fig. 6). The first is, as a rule, long; it is composed of an infolding of the plasma membrane of the neuron, an intercellular space and a slender process of a glial cell. The second segment from the end of the glial process to the beginning of the X-body is always short; it is characterized by the presence of a desmosome-like junction. The third part consists of a labyrinth of cisternal spaces lined by membranes which are continuous with the infoldings of the surface membrane of the nerve cell.This investigation was supported by U.S.P.H.S. Grant NB 02145-04. The skillful assistance of Mrs. Cynthia Jones, Mr. Stanley Brown and Mr. Douglas Gasner in different phases of this work is gratefully acknowledged.     

Distribution of heavy metals in the hippocampal region of the guinea pig

Summary With the present modification of Timm's sulfide silver method all parts of the hippocampal region show a distinctly stratified staining pattern, suggesting large regional differences in the content of heavy metals.The stain is largely confined to distinct grains, partly associated with neuronal somata and partly dispersed in the neuropil. Work in progress supports the idea that the grains in the neuropil are synaptic boutons, as has been shown previously for the mossy fibre layer.The staining pattern has been compared in detail with the fields and layers of the hippocampal region as delineated by cyto- and fibroarchitectonics. Previous concepts of the subdivision of this cortical region are confirmed and supplemented.The sulfide silver pattern of the guinea pig hippocampal region is fundamentally similar to that of the rat. However, the entorhinal area, the regio inferior hippocampi, and the dentate area show notable differences in the staining pattern between the two species.We are indebted to Mrs. E. Kjaer Hansen, Mrs. L. Knudsen, Mr. B. Krunderup, Mr. A. Meier, Mr. Th. Nielsen, Mrs. B. Sørensen, and Miss M. Sørensen for skilful technical assistance.This study was supported in part by U.S.P.H.S. Grant NS 07998.Permanent address: Anatomical Institute, University of Oslo, Norway     

The nature of thymidine kinase in the human-mouse hybrid cell

In order to characterize the thymidine kinase in human-mouse somatic cell hybrids derived from mouse parental cells lacking thymidine kinase, we have examined the electrophoretic migration on starch gel and the heat sensitivity of this enzyme in human, mouse, and hybrid cells. The enzyme of hybrid cells migrates similarly to that of human fetal liver and human diploid fibroblasts and faster than that of either L or A₉ mouse cells. It is less sensitive to heat than that of the mouse cells. Therefore, the human group E chromosome provides human thymidine kinase for the hybrid cell. The electrophoresis of thymidine kinase makes possible the search for variants.Aided by U.S.P.H.S. Grant No. HD 00486.     

Studies on the nucleus of candida spp

Summary Nuclear division inCandida albicans during budding and blastospore formation is described. Classic mitotic division as it occurs in the higher ascomycetes is not seen. Instead, the semi-lunar (crescentic) chromatinic material in the nucleus increases so as to fill the nuclear vesicle, often assuming a toroid-like aspect. The nucleus then divides into two crescentic masses one of which migrates to the daughter cell. No external centriole or spindle apparatus could be observed. No chromosomes could be resolved. Nuclear division in the mold phase duplicated that found in the yeast phase. Colchicine treatment of yeast phase cells resulted in the appearance of large polynucleate and polyploid cells in one strain ofC. albicans.Supported by U.S.P.H.S. Grant E-1700.     

A comparative study on sub-filament organization in primary myofilaments of basalar direct flight and tibial extensor muscles of the lepidopteran,Achalarus lyciades

Summary Primary myofilaments of direct flight muscle fibers are hexagonally arranged, are surrounded by six secondary myofilaments, and are composed of two sub-unit-fibrils, 90–120 Å in diameter, at mid-sarcomere levels. Primary myofilaments are resolvable into electron-densities 15–25 Å in diameter, which number 3–4 in each sub-fibril at mid-sarcomere levels, and number 6–8 elsewhere. Primary myofilaments of tibial extensor muscle are not found in hexagonal arrays, are surrounded by 10–12 secondary myofilaments, and are resolvable into electron densities which are 15–25 Å in diameter similar to primary myofilaments of basalar flight muscle. However, a binary sub-fibril structure at mid-sarcomere levels is lacking in tibial extensor muscle fibers.The functional significance of the two-sub-fibril organization of myofilaments at midsarcomere levels in basalar direct flight muscle is not known, but may be related to the high rate of excitation-contraction cycles in these muscles.Supported by U.S.P.H.S. No. NB-06285. — The author wishes to express his grateful appreciation for the technical assistance given by Mrs. Ann Florendo during the course of this investigation.     

The effect of monoamine depleting drugs upon the synaptic bars in the inner ear of the bullfrog (Rana catesbeiana)

Summary Reserpine and guanethidine produce a highly significant reduction in electron density of the synaptic bars in the sensory cells of the bullfrog labyrinth. When amphetamine is administered simultaneously with guanethidine, the density of the synaptic bars is similar to those of untreated frogs. p-Chloramphetamine has no significant effect upon the electron density of synaptic bars. These observations are discussed in the light of what is known of the biological effects of these drugs, and are taken to indicate that the synaptic bars could be intracellular storage sites for a monoamine that mediates the synaptic contacts between the sensory cells and afferent nerve fibres. It is suggested that the monoamine involved is a catecholamine.Both of us thank Mrs. J. Birch and Miss J. Sutcliffe for their technical assistence. One of us (M. P. O.) was supported by a U.S. National Research Council Senior Research Associateship (1967–1968) during the earlier phase of this work, and we are both indebted to the Italian Consiglio Nazionale delle Ricerche for a grant (No. 69.01697.119.3) which financed the latter stages of this study.     

Uptake of radioactive thymidine and cytidine by Ehrlich ascites tumor cells in different stages of growth

Summary In Strong A female mice, the Ehrlich ascites tumor inoculated into the peritoneal cavity grows exponentially for the first 7 days with a doubling time of about 36 hours. The tumor enters then into a late stage during which the number of tumor cells in the peritoneal cavity does not increase. The uptake of intraperitoneally injected thymidine decreases from the exponential to the late stage, mostly because of a decrease in the fraction of cells in DNA synthesis. During the exponential phase, the uptake of thymidine is a function of the amount of radioactive thymidine injected per tumor cell, the utilization decreasing with increasing cell dose. The uptake of intraperitoneally injected cytidine decreases slightly with time after inoculation although the fraction of tumor cells in RNA synthesis remains constant.Dedicated to Professor Friedrich Wassermann with admiration and affection on the occasion of his 80th birthday.This investigation was supported by U.S.P.H.S. Grant CA-05667. The author is a U.S.P.H.S. Research Career Development Awardee.