The origin and fate of secretion in the follicle cells of tunicates

Summary The vacuolization of the outer follicle cells which accompanies maturation of the oocytes of the tunicates Ciona intestinalis and Molgula manhattensis is associated with the dissolution of heterogeneous secretion granules in these cells. The secretion granules, in turn, have a dual origin with one component derived from the endoplasmic reticulum while the other component arises in association with the Golgi complexes. Stages in the morphogenesis of secretion are described.This study was supported by a research grant (GM-09229) and a Career Development Award from the National Institute of General Medical Science, United States Public Health Service.     

Theory of hemoglobin facilitated oxygen transport

The transport of oxygen in a hemoglobin-saturated medium is theoretically investigated using classical transport theory. It is found that all the chemical complexes can be expressed as a single function of oxygen pressure. A potential difference together with apH shift is predicted to occur across the medium. This research was supported by the United States Public Health Service Training Grant No. 5-T1-GM-833 from the National Institute of General Medical Sciences. This research was supported by a United States Public Health Service Research Career Program Award 5-K6-GM-18,420 from the National Institute of General Medical Sciences.     

Electron microscope studies on the origin and maturation of yolk in oocytes of the tunicate,Ciona intestinalis

Summary The origin of proteinaceous yolk in oocytes of Ciona, intestinalis appears to involve the activity of two kinds of vesicles derived from the Golgi complex. One kind of vesicle contains a granular product of considerable density while the contents of the other type of vesicle are of low density. Both types of vesicles become widely dispersed in the ooplasm during vitellogenesis. The high-density vesicle exhibits greater size variation than the lowdensity vesicle. The growing yolk globules possess an external often folded membrane enclosing both granular and vesicular elements. The granular-vesicular bodies are observed in wide size ranges and they appear to arise and increase in size by fusion or incorporation of numerous high-density vesicles, low-density vesicles, and smaller granular-vesicular bodies. The relationship of the developing yolk globules to ribosomes, pinocytotic vesicles, and vesicular endoplasmic reticulum is illustrated.This investigation was supported by research grants (GM-09229, HD-00699) from the National Instituts of Health, U. S. Public Health Service and a Career Development Award (GM-11,524) from the National Institute of General Medical Science.     

Growth of a water strain ofLeptospira in synthetic media

Pertinent parameters of growth of a water strain ofLeptospira in synthetic media are described. Growth rates as a function of aeration, temperature, and substrate concentration were determined. Evidence is presented for the production of acetate and CO₂ from long-chain fatty acids. A marked drop in pH was shown to result from the accumulation of acetate during growth in synthetic medium. Growth was initiated at pH values from 5.2 to 7.7. An absolute CO₂ requirement for initiation of growth was demonstrated. Growth is also described with acetate as the sole carbon and energy source, demonstrating that leptospires are capable of fatty acid synthesis.This investigation was supported by Public Health Service grant AI-05440 from the National Institute of Allergy and Infectious Diseases, and by Public Health Service predoctoral fellowship (1-Fl-GM-40, 062-01) to the senior author from the National Institute of General Medical Sciences. Technical assistance of Mr. Howard Young is gratefully acknowledged.     

Cytogenetics of the grasshopper Moraba scurra

Summary The cytology of a male individual of the grasshopper Moraba scurra which was heterozygous for a complex translocation involving breaks in four different, non-homologous, chromosomes, is described. Chains of up to eight chromosomes occur at first metaphase. Certain chromosomes which never normally show more than a single chiasma form two chiasmata with a fairly high frequency in this individual.Supported by Public Health Service Grant No. RG7212-Cl, from the Division of General Medical Sciences, U.S. National Institutes of Health.     

The development and evaluation of immunodiffusion,immunofluorescence and physiological tests for the differentiation of atypical trichophyton rubrum and T. mentagrophytes isolates

Five laboratory procedures: 1) immunodiffusion, 2) immunofluorescence, 3) in vitro hair perforation, 4) pigment stimulation, and 5) a urease test were compared for their ability to differentiateT. rubrum fromT. mentagrophytes. Of the physiological tests, thein vitro hair perforation technique was the most reliable for differentiating the two species. With the serological tests, the organisms were not differentiated by immunodiffusion, but if appropriate dilutions of the conjugates were used in immunofluorescence testing, most isolates could be differentiated.A portion of a Dissertation submitted by the senior author to the University of North Carolina in partial fulfillment of the requirements for the degree of Doctor of Public Health in the School of Public Health. Training was provided by the Laboratory Director's Program which is supported by Training Grant TO1 GM 00567-07 from the National Institute of General Medical Sciences, National Institutes of Health, United States Public Health Service. The laboratory research was performed at the Laboratory Division, Center for Disease Control, under the supervision of William Kaplan.     

The liver of the slender salamander Batrachoseps attenuatus

Summary The structure of the crystalline inclusions found in Batrachoseps liver cells is described and it is shown that the most symmetric unit cell upon which the crystal lattice is built is a face-centered cube. Taking into consideration the physical properties of a face-centered cubic structure, an attempt is made to determine the nature of the macromolecules that comprise the crystal. It is concluded on the basis of available evidence that the macromolecules probably represent serum lipoproteins. The intracellular synthesis of the crystals and the possible functions they may subserve in the animal are discussed. A comparison is made between the crystals and granules in rat hepatocytes discussed by Bruni and Porter (1965).Research supported by grant RG-6729 from the Institute of General Medical Sciences, National Institutes of Health, United States Public Health Service.     

Mitochondrion-desmosome complexes in human hepatocytes

Summary Mitochondrion-desmosome complexes similar to those seen in other epithelia were observed in hepatocytes from normal and diseased human livers of children and adults. Their occurrence could not be explained by random distribution of mitochondria in the cells. The close associations of mitochondria with desmosomes supported the hypothesis that the latter might be special areas of intercellular ionic diffusion between hepatocytes.This work was supported in part by United States Public Health Service Grants AI-1059 and TI AM-5384 from the National Institute of Arthritis and Metabolic Diseases, 5 MOl FR 000-50 from the General Clinical Research Center, HD 00674 from the National Institute of Child Health and Development and by a grant from the Life Insurance Medical Research Fund G-65-50.The author is very grateful to Dr. Alex B. Novikoff for the use of the facilities of his laboratory (supported by United States Public Health Service Grant CA-06576), to Mr. Nelson Quintana and Mrs. Julie Windsor for their superb technical assistance and to Miss Marianne Van Hooren for preparation of the photographs.     

A reinvestigation of the nucleolus-organizing regions in the salivary gland nuclei of Drosophila melanogaster

Comparisons were made of the morphology of the proximal region of the salivary gland X-chromosome of D. melanogaster following a number of different staining procedures. Azur B was found to be the most satisfactory staining method for identification of the nucleolus. The states of eu- and heterochromatization (sensu Prokofyeva-Belgovskaya) of the bands in the proximal region—particulary striking in the mirror-image duplication of the R(1)2, ring-X, chromosome—contribute to the variability in the banding-pattern, and consequently the refractoriness of this region to cytological investigation. No nucleolus was ever found to be associated with the group of bands presumed to be the Y-chromosome.This investigation was supported in part by a U.S. Public Health Service Research Grant, GM 15009, from the Institute of General Medical Sciences of the National Institutes of Health, and in part by a grant from the Finnish National Research Council for Sciences.     

Phosphorylation and acetylation of glucosamine in germinating mung bean seeds

With the aim of elucidating the pathway of glucosamine in higherplants, studies were made on the enzymatic phosphorylation ofthis aminosugar and the subsequent acetylcoenzyme A-mediatedacetylation of the phosphate ester to N-acetylglucosamine 6-phosphate,as catalyzed by enzyme preparations obtained from germinatingmung bean seeds. Deaminase activity for glucosamine 6-phosphatewas detected. The reaction product was identified to be fructose6-phosphate. ¹This investigation was supported in part by a research grant(GM 11888) from the National Institute of General Medical Sciences,National Institutes of Health, United States Public Health Service.     

Effect of colchicine on the fine structure of the neuromuscular junction

Summary Repeated injections of colchicine into the forearms of normal adult newts led to the disappearance of microtubules within some nerves and a concomitant loss of specialized morphological features at the neuromuscular junction. Within 2 weeks, the postsynaptic folds decreased in height and number, became flattened and eventually disappeared. In addition, nerve terminals in drug-treated animals became separated from the muscle surface and were highly congested with masses of synaptic vesicles. The present findings show that colchicine has an effect on the structural integrity of the neuromuscular junction. These effects could be direct; secondary to retraction of the nerve from the muscle surface; or the result of interference with the proper transport and/or release of neurotrophic substances.Supported by grants from the National Science Foundation (GB 20902) and from the National Institute of General Medical Sciences (TIGM-00105) and the National Cancer Institute (TICA-05055), National Institutes of Health, United States Public Health Service.     

Duplication of the autosomally inherited 6-phosphogluconate dehydrogenase gene locus in tetraploid species of cyprinid fish

Among members of the fish family Cyprinidae,a diploid—tetraploid relationship exists. The present study on electrophoretic patterns of 6-phosphogluconate dehydrogenase indicates that such diploid members as Barbus tetrazonamaintain allelic polymorphism at a single gene locus for this enzyme. Tetraploid members such as the carp and goldfish are endowed with two separate gene loci for 6-PGD. Tetraploid evolution apparently fixed two former alleles of the same locus as two separate gene loci. Furthermore, it appears that after becoming tetraploid, the carp and goldfish developed a separate regulatory mechanism for each locus; thus preferential activation of one or the other 6-PGD locus occurs in different tissues of tetraploid species. This investigation was supported in part by a grant (CA-05138) from the National Cancer Institute, U.S. Public Health Service, and in part by a research fund established in honor of General James H. Doolittle. Contribution No. 4-68, Department of Biology, City of Hope Medical Center.Dr. Bender is a recipient of International Postdoctoral Fellowship 3 F05-TW-01198-0152 from the U.S. Public Health Service.     

The effect of newer tubercle bacillus digestion and decontamination procedures on fungi causing pulmonary diseases

The paper concerns the effect of the newer tubercle bacillus digestion and decontamination procedures on the principal pulmonary mycotic disease agents in sputum The digestion-decontamination procedures used were: 1) N-acetyl-L-cysteine - sodium hydroxide, 2) dithiothreitol - sodium hydroxide, and 3) trisodium phosphate - Zephiran.A portion of a Dissertation submitted by the senior author to the University of North Carolina in partial fulfillment of the requirements for the degree of Doctor of Public Health in the School of Public Health. Training was provided by the Laboratory Director's Program which is supported by Training Grant 5 T1 GM 567 from the National Institute of General Medical Sciences, National Institutes of Health, United States Public Health Service. The laboratory research was performed at the Laboratory Division, Center for Disease Control, under the supervision of the junior author.     

On the regulation of D-ribose metabolism in E. coli B-r. I. Isolation and characterization of D-ribokinaseless and D-ribose permeaseless mutants

Summary A presumed single site mutation designated leu-500, affects both the basal expression and response to the leucine repression signal by the leucine operon of Salmonella typhimurium. The distantly located supX mutation suppresses the leucine auxotrophy imposed by the leu-500 mutation by raising the level of basal expression while maintaining the abnormal regulation. An additional type of suppressor mutation which is closely linked to the leu-500 locus restores essentially normal regulation but maintains the low repressed expression characteristic of the leu-500 strain. The leucine sufficiency of the leu-500 strain with the linked suppressor and the supX leu-500 strains is temperature conditional in that both types require leucine for growth at 42° but not at 37°. These results, which indicate that a single site mutation can simultaneously affect promoter-like and operator-like function, are discussed in terms of DNA superstructure.This investigation was supported by U.S. Public Health Service Research Grant GM-12551 from the National Institute of General Medical Sciences, and is a portion of the work submitted by Lloyd H. Graf in partial fulfillment of the requirements for the hP. D. degree from Duke University. Lloyd H. Graf was the recipient of a predoctoral fellowship award from the National Institute of General Medical Sciences. R. O. Burns is the recipient of a Research Career Development Award from the National Institutes of General Medical Sciences.     

Electron microscopy of the skin of the teleost,Hippoglossoides elassodon

Summary The normal skin of the pleuronectid fish, Hippoglossoides elassodon, is described by light and electron microscopy. The epidermis consists of 5 to 9 layers of cells, the majority of which are squamous cells and the minority mucous cells. The squamous cells are characterized by numerous desmosomes and associated cytoplasmic filaments. The mucous cells accumulate mucous droplets in vacuoles of Golgi origin and are observed apparently in the process of releasing their content at the free surface. The dermis consists of alternating lamellae composed of typical collagen fibers. Pigment cells are of three types: melanophores, iridophores (guanophores), and lipophores.This work was supported by Public Health Service Research Grant CA-08158 from the National Cancer Institute.     

Linkage relationships of Lp and Ag serum lipoproteins with 25 polymorphic markers

Summary Linkage relations of Lp and Ag serum lipoproteins with 25 polymorphic marker systems are examined in a large kindred of over 100 persons. The results indicate that Lp and ESD are probably closely linked and so the Lp locus may also be assigned to chromosome 13. No significant linkage is detected between Ag and the other marker systems.This research was supported by: a Public Health Service Research Career Development Award (1-K3-GM-31, 732) and research grant (GM 16697) from the National Institute of General Medical Sciences.     

Intra- and interspecific chromosomal inversions in the Drosophila bipectinata species complex

Twenty autosomal inversions were detected in the polytene chromosomes of larvae obtained by hybridizing inversion-free strains of the species of the bipectinata complex (D. bipectinata, D. parabipectinata, D. malerkotliana and D. pseudoananassae). Twenty autosomal inversions are also known as extant polymorphisms in these species; fifteen (possibly sixteen) of these inversions are different from those detected in the interspecific hybrids. The available evidence permits reconstruction of chromosome phylogenies deriving malerkotliana, pseudoananassae and a population ancestral to both bipectinata and parabipectinata directly from a common ancestral population. The results of the study support the Carson hypothesis of transitional homoselection during the processes of speciation.Part of this study was incorporated in a section of a thesis submitted for the degree of Doctor of Philosophy in the University of Queensland, Australia; the work was continued under support by a U.S. Public Health Service Research Grant No. GM-11609 from the National Institute of General Medical Sciences to Prof. M. R. Wheeler, University of Texas.     

Chromosomal study in patients with cysts of the jaw,multiple nevoid basal cell carcinomata and bifid rib syndrome

Summary A chromosomal abnormality in a patient with cysts of the jaw, recurrent nevoid basal cell carcinomata and bifid ribs is described. The patient presented a normal female complement, except for the unusual length of one arm of one of the chromosomes No. 1. Her mother, two sisters, and a male child of one of these two sisters presented a similar chromosomal anomaly with no expression of the syndrome. Several possible explanations are discussed.Supported (in part) by a Public Health Service training grant (number 2G-628 PATC) from the Division of General Medical Sciences, and (in part) by a research grant (number E 798) from the National Institute of Allergy and Infectious Diseases.     

Formation of yeast mitochondria III: Biochemical properties of mitochondria isolated from a cytoplasmic petite mutant

A number of biochemical properties of mitochondria from a cytoplasmic petite mutant ofSaccharomyces cerevisiae with an extremely high adenine plus thymine content have been studied.When such particles are isolated by means of standard procedures developed for use with wild-type yeasts they are grossly contaminated by non-mitochondrial membrane fragments. Further enrichment of mitochondria is achieved by non-equilibrium centrifugation in sucrose gradients.Throughout this purification procedure the particles can be shown to retain an outer limiting, as well as a non-cristate inner membrane. In many of their morphological and physical features (size, shape, buoyant density) they resemble mitochondria isolated from the wild type.Although enzymes of the respiratory chain are absent from the mutant particles, their content ofl-malate dehydrogenase, NADP-dependent isocitrate dehydrogenase, and ATPase is comparable to that found in the wild type. The mitochondrial ATPase in this mutant strain is cold stable, oligomycin insensitive, Dio-9 sensitive, and susceptible to inhibition by the F₁ inhibitor of beef heart. The enzyme can be rendered cold labile by its detachment from the membrane, followed by fractionation with protamine sulfate and ammonium sulfate.The existence of mutant particles that are incapable of function in oxidation and phosphorylation but resemble their functional homologues in many other ways raises the possibility that mitochondria are required in the cellular economy for purposes not directly linked to oxidative phosphorylation and electron transport. This hypothesis has led us to suggest that, contrary to models currently under discussion, mitochondria did not evolve as a consequence of endosymbiosis. We propose as an alternative that the mitochondrial organelle evolved as a means of improvement of existing subcellular structures in the primordial (perhaps eukaryotic) cell. Partial autonomy may thus constitute a relatively recent modification; the present-day mitochondrial genome had its origin in nuclear DNA and may have been amplified in a manner not unlike the amplification of ribosomal RNA cistrons in developing oocytes ofXenopus.Supported by Research Grant GM 12228 from the National Institute of General Medical Science, National Institutes of Health, U.S. Public Health Service.Recipient of a Public Health Service Career Award No. GM 05060 from the Institute of General Medical Sciences.     

Metabolic suppressors of a regulatory mutant in Neurospora

The synthesis of a number of enzymes of sulfur assimilation in Neurospora crassa is controlled by the sulfur source. Mutants in one regulatory gene, cys-3, are unable to make any of the enzymes. This locus is thought to specify a macromolecule that is required for the expression of the structural genes. A mutant, scon ^c, of another regulatory gene is nonrepressible for the synthesis of the enzymes. We report here the isolation of suppressed scon ^c strains which are actually the double mutant, scon ^c,cys-3. These strains are phenotypically indistinguishable from single mutants at the cys-3 locus. Thus cys-3 is epistatic to scon ^c. Evidence that the expression of the cys-3 gene is itself controlled is also presented.This work is supported by a Public Health Service grant, GM-08995, from the National Institute of General Medical Sciences. One of us (R.L.M.) is supported by a Public Health Service Career Development Award.