The chromosomes of Arixenia esau Jordan (Dermaptera)

The parasitic insect Arixenia esau, a highly aberrant member of the order Dermaptera, shows n = 30 and has an XY sex determining mechanism. This karyotype is compared with those of the earwigs (Forficulina) and of Hemimerus bouvieri, a member of another aberrant parasitic suborder of the Dermaptera.Supported by Public Health Service Grant GM-07212 from the Division of General Medical Sciences, U.S. National Institutes of Health and by a grant from the Australian Research Grants Committee.     

The chromosomes of Hemimerus bouvieri chopard (Dermaptera)

The parasitic insect Hemimerus bouvieri, of rather uncertain systematic position but probably an aberrant member of the order Dermaptera, shows 2n =7, 2n =8. The chromosomes appear to be holocentric. There is an X₁X₂Y sex chromosome mechanism in the male, and a sex-trivalent is formed at meiosis. The two autosomal bivalents seem to be chiasmate and the members of the sex-trivalent may also be held together by chiasmata, but this is uncertain. In general, these cytological features are similar to those of true earwigs (Forficulina).Supported by Public Health Service Grant GM-07212 from the Division of General Medical Seiendes, U.S. National Institutes of Health and by a grant from the Australian Research Grants Committee.     

The yield of synaptosomes from the cerebral cortex of guinea pigs estimated by a polystyrene bead “tagging” procedure

Summary The number of synaptosomes (pinched-off nerve endings) produced/g guinea pig cortex on homogenizing this tissue under defined conditions is estimated to be in the region of 4×10¹¹ using two different polystyrene bead tagging procedures. This is the same order of magnitude as the number of nerve endings/g cortex calculated from histological estimates given in the literature of the number of neurones in the cortex and the extent of their cortical connexions.This investigation was supported by U.S. Public Health Service Grant no. NB 03928 from the National Institute of Neurological Diseases and Blindness. Dr. Sheridan was a Postdoctoral fellow of the U.S. Public Health Service during the period of his participation in this investigation (1963/64). The electron microscope facilities were provided by the Wellcome Trust. Mr. T.F.J. Hobson, of the ARC Statistics group, Cambridge, kindly advised on statistical aspects of the work. We are most grateful to him, to Miss L. Swales and Mr. G.H.C. Dowe for their skilled technical assistance and to Dr. E.G. Gray for helpful discussions.     

Cytogenetics of the parthenogenetic grasshopper Moraba virgo and its bisexual relatives

An undescribed bisexual grasshopper species closely related to the all-female parthenogenetic Moraba virgo has an X₁X₂Y sex chromosome mechanism which incorporates 7 chromosomes of the ancestral karyotype (the original X and three pairs of autosomes). Apparently three separate chromosomal fusions have occurred, one of these being a tandem fusion followed by a crossover which stabilized it in the sex chromosome system. M. virgo probably arose from an ancestor which had X₁X₂Y males but lacked the tandem fusion present in the new species, the females of virgo having the constitution X₁X₁X₂O.Supported by Public Health Service Grant GM-07212 from the Division of General Medical Sciences, U.S. National Institutes of Health, and by a grant from the Australian Research Grants Committee.     

Effects of group environment on the mother-infant relationship in pigtailed monkeys (Macaca nemestrina)

Behavior of sixMacaca nemestrina mother-infant pairs was observed in two different environments; three pairs were part of a large group in a compound and three pairs were housed in individual laboratory cages. At weeks 14–15 of the infants' lives, group mothers were more retentive of their infants than caged mothers; group infants spent more time in ventral contact with mother and nursed more than did caged infants. The authors conclude that the greater dependence of an infant raised in a potentially dangerous group setting is due to a more protective mother rather than to a more fearful infant.This work was supported by grant no. FR 00166 from the National Institutes of Health, U. S. Public Health Service.Reprints may be obtained from:Primate Information Center, I-321 Health Sciences Building, University of Washington, Seattle, Washington 98105, U.S.A.     

Control of proliferation in two cell linesin vitro

Summary In two types of cells growing as monolayer cultures (an established line of Chinese hamster cells and a newly obtained strain of Rat Fibroblasts) no evidence is found for proliferation control by contact inhibition of mitosis or by cell-produced chemical inhibitors. Under the particular conditions of these experiments, the intracellular concentration of a multiplication-stimulating factor (MSF) associated with fetal calf serum appears to play a regulating role. This factor is degraded continually by proliferating as well as by non-proliferating, plateau phase cells. A model is proposed in which the intracellular concentration of MSF is governed by: the amount of MSF available to the cell from the culture medium; the permeability and amount of cell membrane accessible for diffusion (or transport) of MSF; and the rate of its degradation. It is hypothesized that mitosis only occurs if the concentration of MSF exceeds a critical value and that this critical value is a characteristic of the cell type. Consistency of the model with existing data concerningin vitro cell proliferation is discussed.This work was supported by Grants CA-04542 and CA-10372 from the National Cancer Institute, National Institutes of Health, U.S. Public Health Service.Biophysics trainee under United States Public Health Service Training Grant GM-00712 from the National Institutes of Health.Holder of a Dernham Senior Fellowship in Oncology from the American Cancer Society, California Division.     

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.     

Analysis of chromosome 4 inDrosophila melanogaster. I. Spontaneous and X-ray-induced lethals

An analysis of 17 spontaneous and 37 X-ray-induced lethal mutations on the fourth chromosome ofDrosophila melanogaster has revealed a minimum of 22 loci on this microchromosome capable of mutating to lethality. A few of these loci had been identified earlier by their visible alleles but 16 are new discoveries. Seven of the 22 lethal loci are situated within that proximal section of the right arm of chromosome 4 delimited by theMinute-4 deficiency.Genetic tests indicate that two translocations and five deletions are included among the lethals of X-ray origin. No chromosomal aberrations were found among the spontaneous mutants. Allelism was encountered both within and between lethals from the two groups.Three independent estimates of the total number of lethal loci to be expected on this small autosome are presented. These appraisals are based on (1) the size of theMinute-4 deficiency, (2) the number of bands in salivary chromosome 4, and (3) the frequency of recurrence among the lethals. Considering the uncertainties inherent in each determination, the three estimates (34, 35 and 38) show remarkably good agreement.This investigation was supported in part by U.S. Public Health Service Research Grant GM 11627-01, from the Division of General Medical Sciences.     

Analysis of blue-green and red algal ribosomal-RNAs by gel electrophoresis

Summary Ribosomal-RNAs of two species of red algae (Porphyridium aerugineum and Griffithsia pacifica) and a blue-green alga (Phormidium persicinium) were examined by the method of polycrylamide gel electrophoresis. The results of this study indicate that red algal cytoplasmic rRNAs have molecular weights (1.21 m and 0.54–0.58 m) which are the lowest of any other known for an eukaryotic organism; but a 130,000 dalton gap remains between these values (for the heavy rRNA component) and those for prokaryotic rRNAs (1.06–1.08 m and 0.56 to 0.59 m). Although the cytoplasmic rRNAs of the red algae are distinctly eukaryotic in size, the chloroplast rRNAs of these organisms exhibit physical characteristics (molecular weights and mode of breakdown) which make them more like blue-green algal rRNAs than like the rRNAs of other chloroplasts.This work was supported by Grant GB-18144 from the National Science Foundation, Washington, D.C. (to J.R.) and a National Institutes of Health Predoctoral Fellowship, U.S. Public Health Service, Washington, D.C. (to G.P.H.). Abbreviation used in this report: m=×10⁶ daltons.     

Vacuolar protein in apical and flower-petal cells

Summary Vegetative apices, floral apices and flower petals of five Solanaceae (potato, tomato, tobacco, petunia and nightshade) and of corn and Nigella were examined with an electron microscope for the presence of protein bodies in the cell vacuoles. Electron-dense bodies were found in vacuoles of all plants investigated but not in every tissue examined. The bodies observed in the apices are similar to the protein bodies previously found in tomato leaves where they appear to be related to the presence of chymotrypsin inhibitor I protein (Shumway et al., 1970). The bodies appeared in very young cells in small vacuoles, disappearing as the cell matured. They are apparently related to the growth and development of the new cells. The results suggest that plants may regulate specific proteins within the apical region through selective synthesis and degradation of proteins accompanied by compartmentalization in the vacuole.Scientific Paper No. 3822, College of Agriculture, Washington State University, Pullman, Project 1791. This investigation was supported in part by the State of Washington Initiative Measure 171 funds, the Graduate School Research funds, by the U.S. Department of Agriculture, Cooperative State Research Service Grant 915-15-29, and U.S. Public Health Service Grant 2K3-GM-17059.Program in Genetics and Department of Botany.Program in Genetics.     

Further studies on polyploid amphibians (Ceratophrydidae)

The comparative DNA values were measured in three species of South American frogs belonging to the family Ceratophrydidae: Odontophrynus cultripes (2n=22), O. americanus (2n=44) and Ceratophrys dorsata (2n=104). Nuclei of erythrocytes, liver, kidney, pancreas and testis were used for measurements. The results obtained confirmed polyploid evolution in the family Ceratophrydidae. The relative DNA values of these three species conformed to the expected 124 ratio. — In general, the proportional increase in nuclear volume was observed in corresponding tissues of tetraploid and octoploid species.Supported by a grant (GM-14577-01) from National Institute of General Medical Sciences — U.S. Public Health Service.Supported by grants from CNPq, UFMG and Rockefeller Foundation.     

Asymmetry of heteropycnosis in tetraploid cells of a grasshopper

In XO male grasshoppers (Acridoidea and Eumastacoidea) X-chromatin is negatively heteropycnotic in spermatogonial mitoses. In neo-XY species which have a fusion between the original X and an autosome it is usual for the former alone to show negative heteropycnosis. This is the case in the Australian Morabine grasshopper species P52a. In tetraploid spermatogonia of this species, however, which contain two neo-X's and two neo-Y's, only one of the neo-X's has a negatively heteropycnotic left limb, the other X having the same degree of condensation as the autosomes. This novel type of behavior is compared with the heteropycnosis of one of the two X's in the somatic cells of female mammals. It is concluded that the asymmetry of condensation of the two X's in tetraploid spermatogonia of P52a demonstrates the existence of a fundamental cellular mechanism which is inherent and only expressed under the abnormal condition of tetraploidy.Supported by Public Health Service Grant GM-07212 from the Division of General Medical Sciences, U.S. National Institutes of Health and by a grant from the Australian Research Grants Committee.     

On the role of isoleucyl-tRNA synthetase in multivalent repression

An isoleucine auxotroph of Salmonella typhimurium was derived from a merodiploid strain (containing the F-14 episome from Escherichia coli) that contained two copies of the structural genes concerned with isoleucine and valine biosynthesis. A haploid derivative, strain TU6001, having the same growth properties as the original merodiploid mutant was found to have normal biosynthetic enzymes and an altered isoleucyl-tRNA synthetase. The K _m for isoleucine was increased by about 200-fold over that for the wild-type enzyme. All five enzymes in the isoleucine and valine biosynthetic pathway were derepressed relative to wild-type enzyme levels. A partial revertant of strain TU6001 was isolated which had properties that were intermediate between those of the mutant and the wild type (i.e., intermediate growth dependence on exogenous isoleucine, intermediate activity of isoleucyl-tRNA synthetase, and intermediate derepression of biosynthetic enzymes). The properties of strain TU6001 were demonstrated to be simultaneously transferable by transduction (using P_LT22 H₄ bacteriophage) of a single genetic locus, linked to pyr A, which has been designated ilv S. It is concluded that some function of the isoleucyl-tRNA synthetase is important in repression of the isoleucine and valine biosynthetic enzymes.Supported by grant GM 12522 from the National Institute of General Medical Sciences, U.S. Public Health Service. J. M. B. received a U.S. Public Health Service Postdoctoral Fellowship 1-F02-GM-30, 650-02.     

The distribution and form of the endoplasmic reticulum during spermatogenesis in the crayfish,Cambaroides japonicus

Summary The form and differentiation of the endoplasmic reticulum has been studied in the developing sperm of the crayfish, Cambaroides japonicus. Throughout development a relationship between the nuclear envelope and cytoplasmic portion of the endoplasmic reticulum has been shown to exist. Furthermore, large contributions of material from the nuclear envelope to extranuclear cytoplasmic systems has been noted in the development of early spermatids and nearly mature sperm.A sequential predominance of several types of endoplasmic reticulum has been described in the differentiating sperm. An agranular vesicular reticulum is the most common in the early stages although annulate lamellar stacks and rough surfaced stacks are scattered randomly throughout the cytoplasm. Blebs of the nuclear envelope appear to contribute rough surfaced reticulum to the cytoplasmic system in the early spermatid. A fusion of vesicular elements results in the formation of the dense filamentous reticulum which is typical of the nearly mature sperm. Densely packed lamellae develop on the nuclear envelope in the maturing sperm and are connected to both the nuclear envelope and filamentous endoplasmic reticulum. The possible relationships of these lamellar groups to mitochondria or Golgi is discussed.Supported in part by Grant No B-2314 of the National Institute of Neurological Diseases and Blindness, U.S. Public Health Service.Predoctoral Research Fellow of the National Institute of Neurological Diseases and Blindness, U.S. Public Health Service.     

Localized negative interference, some of its manifestations and biological function

Summary The theory for high (or localized) negative interference developed byBarricelli andDoermann (1960) and tested on phage T4 data is here used to interpret data on phage (Amati andMeselson, 1965) andAspergillus (Pritchard, 1960). The analysis calls attention to the differences and the startling similarities between the three quite unrelated organisms with respect to this phenomenon.The biological function of localized negative interference appears to be a reduction of recombination frequency between markers at intermediate map distances without reducing the recombination frequency at the smallest map distances where recombination approaches the minimum frequency required for an efficient crossover mechanism (calculated in the text). In avoiding separation by excessive recombination, the reduction of recombination frequency at intermediate map distances may promote the spreading of groups of linked mutant factors when they happen to be collectively but not individually advantageous to the organism.This research was supported by research grant GM-12581 from the Division of General Medical Sciences of the National Institutes of Health, United States Public Health Service. An IBM 650 computing machine has been used by the authors at the University of Washington Computing Center, Seattle, Washington.     

Genetic variation in the carbonic anhydrase isozymes of macaque monkeys. I. The radioimmunosorbent assay

A radioimmunosorbent technique is described which is capable of independently detecting both isozymes of carbonic anhydrase, CA I and CA II, in concentrations as low as 1 ng/ml. The technique is used to quantitate the different electrophoretic variants of red cell CA I as well as levels of CA II in the pig-tailed macaque, Macaca nemestrina.Supported by U.S. Public Health Service research grant GM-15419.U.S. Public Health Service Predoctoral Trainee (GM-71-14).     

Detection of Candida albicans mannan by immunodiffusion,counterimmunoelectrophoresis, and enzyme-linked immunoassay

Anti-mannan was produced in rabbits after peptidoglucomannan in adjuvant was injected. The antiserum was used to detect mannan by immunodiffusion and counterimmunoelectrophoresis (CIE) in gel and by sandwich enzyme-linked immunosorbent assay (ELISA). The antiserum detected lower concentrations of mannan of serotype A than of serotype B. Except in CIE, the reactions were more pronounced at 4°C than at higher temperatures. CIE detected 0.8 g/ml mannan A or 12.5 /ml mannan B. Sandwich ELISA detected 3 ng/ml mannan A or 10⁵ ng/ml mannan B. Mannan was not detected in the serum of patients or rabbits with candidiasis.Use of trade names is for identification only and does not constitute endorsement by the Public Health Service or by the U.S. Department of Health, Education and Welfare.     

Some cytochemical correlations between oxidase activity (cytochrome and peroxidase) and chemical structure of bis(phenylenediamines)

Summary A series of 17 bis(phenylenediamine) derivatives have been prepared and compared with 3,3-diaminobenzidine (DAB) with regard to their ability to demonstrate cytochrome oxidase activity, peroxisome activity, horseradish peroxidase activity, erthrocytic peroxidase activity in cytochemical preparations, and bovine catalase activity in in vitro experiments. The results are tabulated, some illustrative photomicrographs are included and interesting correlations are discussed.This investigation was supported by a research grant (CA-02478) from the National Cancer Institute, U. S. Public Health Service.Acknowledgement for technical assistance is due Charles Hatton and William Brown.     

The ultrastructure of the layers enveloping yolk-forming oocytes from Triturus viridescens

Conclusion The peripheral membranous and extracellular layers of oocytes at the onset of yolk formation were studied by electron microscopy. It was shown that three cellular layers are present at this time. The outer or surface epithelium contains typical squamous cells. The middle or theca is the connective tissue layer which contains fibroblasts, blood vessels, and collagen fibers. The inner or follicular epithelium proper consists of compactly arrayed follicle cells that have distinct cell boundaries. Two extracellular layers were observed, a coarse granular homogeneous layer and a dense zona radiata. Macrovilli (0.2 in diameter), extensions from the follicle cells, project through the extracellular layers into the peripheral cytoplasm while more numerous microvilli (0.1 in diameter) project up to the dense matrix of the zona radiata. The plasmolemma separating the peripheral cytoplasm from the follicle cells is completely irregular; it forms microvilli. The relations of the enveloping layers as seen with both light and electron microscopes are discussed.This investigation was supported by a Public Health Service research grant (5803-C3) and research career program award (K-3-5356) from the Division of General Medical Sciences.     

Vacuolar protein bodies in tomato leaf cells and their relationship to storage of chymotrypsin inhibitor I protein

Summary Electron microscopy of leaves of tomato has shown that tissue containing chymotrypsin inhibitor I protein has protein in the cell vacuoles. The vacuolar protein was found either as many small bodies or as few large bodies. The data indicate that the vacuole is a temporary storage site for protein which may play an important role in growth and development of the plant. This strongly suggests that the plant-cell vacuole is something more than a site for terminal deposition of waste products. The system offers an unusual opportunity to study the biochemistry and ultrastructure of synthesis, vacuolar deposition, and recall of a well-characterized plant protein.This work was supported in part by Washington State Medical and Biological funds, U.S. Public Health Service Grants 2K3GM17059 and GM12505, and by U.S.D.A. C.S.R.S. Grant No. 915-15-29. College of Agriculture scientific paper 3442, Projects 1791 and 1996.Program in Genetics and Department of Botany.Department of Agricultural Chemistry.Department of Agricultural Chemistry. Research Career Development Awardee of the U.S. Public Health Service.