Studies on the red cell adenosine deaminase polymorphism in Rome

Summary The red cell adenosine deaminase phenotype has been determined in 320 hemolysates from unrelated healthy individuals living in Rome. The gene frequencies were ADA¹=91.1 and ADA²=8.9.Supported by a grant of Consiglio Nazionale delle Ricerche (CNR)     

A simple approach for discovering common nonelectrophoretic enzyme variability: A heat denaturation study in Drosophila melanogaster

A simple procedure is described to detect genetic heterogeneity within electrophoretic classes at a locus in Drosophila, based on electrophoresis and heat denaturation studies. Temperature-resistant (tr) and temperature-sensitive (ts) isoelectrophoretic alleles at the phosphoglucomutase locus (Pgm) are present at polymorphic frequencies in natural and in laboratory populations of Drosophila melanogaster.This work has been supported by a grant from the Consiglio Nazionale delle Ricerche (C.N.R.).     

Karyotype evolution in cell lines of Drosophila melanogaster

The chromosomal changes occurred in two independent cell lines (GM₂ and GM₃) of Drosophila melanogaster maintained in medium supplemented with serum and in serum-free medium were compared. In both culture conditions and in both lines a chromosomal evolution was revealed. Structural and numerical variations were analysed. The breaks giving rise to rearrangements were at heterochromatic level. Moreover, a tetraploidisation followed by loss of chromosomes or of portions of chromosomes recalls an analogous cycle observed in human cells.This work was supported by a grant of the Consiglio Nazionale delle Ricerche, Roma.     

On the fungitoxicity of some new thiocyanatopyrazole derivatives: Electron microscopical study in trichophyton mentagrophytes

Four thiocyanatopyrazole derivatives were synthesized and their fungistatic activity was demonstrated in vitro against a number of dermatophytic fungi. In Trichophyton mentagrophytes, the most active compound induced an unusual increase of the plasma membrane with production of intra and extracytoplasmic complexes, a deterioration of nuclear and mitochondrial membranes and a formation of autophagic-like vacuoles. Plasmolysis, accompanied by an almost complete disorganization of cytoplasmic structures, seemed to be the final event. A possible mechanism of action of the compounds was discussed.Investigation supported by a grant from Consiglio Nazionale delle Ricerche of Italy (Contract No. 7500536).     

Red cell glutamic-pyruvic transaminase gene frequencies in the region of the Po delta (Ferrara,Northern Italy)

Summary The red cell glutamic-pyruvic transaminase phenotype has been determined in 294 individuals from the region of the Po delta (Ferrara, Northern Italy). No correlation with past malarial morbidity has been detected. The gene frequencies found in this survey are similar to those reported for other Caucasian populations. One GPT ³ GPT ¹ individual has been found.Supported by a grant of the Consiglio Nazionale delle Ricerche (CNR).     

The juxtaglomerular apparatus in the mesonephros of Newt (Triturus cristatus)

Summary 1)As in mammals, the juxtaglomerular apparatus of the Newt (Triturus cristatus) is composed by cells of the media of the afferent glomerular arteriole and by cells of the intermediary tubule. 2) The cells of the media of the glomerular arteriole are of two different types: granular and agranular cells. 3) The intermediary tubule is formed by dark and light cells. 4) Part of interrenal body is located close to glomerular arteriole and intermediary tubule.This work was supported by grant of Consiglio Nazionale delle Ricerche of Italy (C.N.R.) N. 115/815/04677.     

Homing behaviour of pigeons disturbed by application of an olfactory stimulus

Summary Experiments designed to test the olfactory hypothesis of pigeon navigation by application of odorous substances to the birds' beaks and nostrils had shown until now variable results which have been interpreted differently. Using a new procedure, we were able to obtain consistent results. In each of the ten experiments performed, pigeons treated with -pinene were randomly oriented whereas control birds were not. Increase of homing time in experimental birds was also confirmed.This work was supported by a grant from the Consiglio Nazionale delle Ricerche.     

The distribution of repetitive DNA in the chromosomes of cultured cells of Drosophila melanogaster

The distribution patterns of different stains (orcein, quinacrine and Giemsa) in an established cell line of Drosophila melanogaster (GM₃ WS) were compared. Each chromosome stained both with quinacrine and with Giemsa shows up a specific banding pattern for heterochromatin. The comparison between the two patterns suggests a hypothesis concerning the significance of the fluorescence; moreover it permits the conclusion that heterochromatin in D. melanogaster mitotic chromosomes is all constitutive and that there is a correspondence between repetitive DNA and sections poor in mappable genes.This work was supported by a grant of the Consiglio Nazionale delle Ricerche Roma.     

Gene frequencies of adenylatekinase polymorphism in the Roman population

Summary The red cell AK phenotypes of 841 hemolysates from unrelated individuals living in Rome have been determined by the starch gel electrophoretic method of Fildes and Harris (1966). The observed gene frequencies were: AK ¹=96.3 and AK ²=3.7.Supported by a grant of the Consiglio Nazionale delle Ricerche (CNR).     

Fine resolution of the karyogram of the quail Coturnix coturnix japonica

Summary The authors have studied the karyogram of the quail Corturnix coturnix japonica in kidney-cells cultures, fixed while still wet and stained with iron haematoxilin and with the Feulgen technique.The diploid complement is 76 plus ZZ in the male and plus ZW in the female (Fig. 3 and 4).The number of microchromosomes is constant; they are Feulgen positive and have a centromere; therefore there is no reason to consider them different from macrochromosomes.Supported by a grant from the Consiglio Nazionale delle Ricerche.     

In vivo observations of nucleolar extrusion in cultured callus cells of a non tumorousNicotiana glauca ×N. langsdorffii hybrid

Summary In vivo observations ofNicotiana glauca ×Nicotiana langsdorffii hybrid callus cells cultured on hanging-drop slides show a continuous pulsating movement of nucleoli containing vesicles from the nucleus into the cytoplasm and the occasional release of the nucleoli into the cytoplasmic stream. The phenomenon is discussed in relation to similar findings in other plant materials, particularly in critical phases of development.Contribution No. 151 from the Laboratorio di Mutagenesi e Differenziamento, Consiglio Nazionale delle Ricerche (C.N.R.), Pisa, Italy. Investigation supported by Consiglio Nazionale delle Ricerche (C.N.R.) under the programme Biology of Reproduction.     

Wine-making by cell-recycle-batch fermentation process

Summary In order to check the overall validity of more efficient fermentation systems to reduce wine-making costs, we carried out an off-skins fermentation of clarified Trebbiano toscano grape-juice, making use of a non-conventional cell-recycle-batch fermentation process. The results showed that the process causes a reduction of the fermentation length as well as an improvement in ethanol productivity and yield and can be conveniently applied to the production of ordinary table wines.This work was supported in part by a grant from the Italian C.N.R. (Consiglio Nazionale delle Ricerche)     

Picric acid-formaldehyde fixation for immunoferritin studies

Summary Picric acid-formaldehyde (PAF) fixative has been compared to other fixatives commonly employed in electron microscopy in order to check its ability to be used in immunoferritin studies. From the results obtained PAF seems to offer very good preservation of the tissue fine structure together with satisfactory detection of immune reactions at ultrastructural level.This investigation was supported by Grants CT 72.00900.04, 73.00449.04, 73.00550.04, from the Consiglio Nazionale delle Ricerche, Italy; and by United States Public Health Service Grants AM-13200 and AM-14928.     

Hybrid prediction in maize. Genetical effects and environmental variations

Summary This paper proposes a method for predicting the performance of multiple cross hybrids on the basis of single cross information, taking into account the specific interaction of the genotypes with the environment.In the prediction model the genetical constants are those used for combining ability analysis, while genotype-environmental interaction terms are defined as linear regression of the genotypical effects on environmental variables.The model was tested by considering the variations arising from the effects of population density; therefore the method was applied in a situation in which the problem was to select the best hybrid-population density combinations.The results obtained show that the model is suitable to represent phenotypical response across densities.However, the material used was not the most suitable to emphasize the improvement of the predictive power of the function when genotype-environmental parameters are considered.This work was supported by a grant from the Consiglio Nazionale delle Ricerche (70.10298.06.115.140).     

Effects of cesium on in vitro myoblast differentiation: An electron microscopic study

Summary This paper describes the microscopic evidence supporting a cesium-induced delay in the fusion of chick embryo myoblast membranes during in vitro myogenic differentiation. We have recently demonstrated that the sharp decrease in the conductivity and permittivity of the membranes of these myogenic cells at the time of fusion is delayed 30 h by the addition of cesium to the culture medium (Santini et al., Biochim. Biophys. Acta 945:56–64; 1988). We report here that this delay in fusion is substantiated by direct microscopic observation and that cesium also induces ultrastructural changes in the myoblast cells themselves. Possible mechanisms by which cesium may cause both the delay in fusion as well as the ultrastructural changes observed are discussed. This investigation was partially supported by an Italian Consiglio Nazionale delle Ricerche grant 85.00.304.02 (to P. L. I.).     

Biosynthesis of sulphur amino acids in Saccharomyces cerevisiae

A number of strains of Saccharomyces which produce sulphite by sulphate reduction were examined from an enzymatic and genetic point of view.There are a number of mechanisms that regulate this activity. All of these mechanisms involve the sulphite-reducing activity. In the strains examined, reduced function as a result of mutation in the Sr-locus (affecting H₂S-NADP oxidoreductase EC 1.8.1.2), repression of biosynthesis of the enzyme because of a mutation below the specific locus, and inhibition of the enzyme by endogenous factors were found to be responsible. The production of sulphite can also be connected with a complex state of heterozygosity.It is probably this multiplicity of biochemical and genetic mechanisms that accounts for the frequency with which the production of sulphite is observed in wild strains in nature.This investigation was supported by a research grant of C.N.R. (Consiglio Nazionale delle Ricerche, Roma).     

Mycoplasma development and cell alterations in white clover affected by clover dwarf an electron microscopy study

Summary The presence of mycoplasma has been demonstrated in the phloem of leaves of white clover (Trifolium repens L.) affected by clover dwarf. Mycoplasma-like bodies were found both in parenchyma and companion cells and in sieve elements.In young parenchyma and companion cells mycoplasma-like bodies appeared as round or oval particles with high ribosomal content, delimited by a ribosome-bearing membrane. Their diameter ranged between 50 and 400 nm. In mature sieve elements they were larger, more pleomorphic, and showed a central clear area containing presumed DNA filaments. Budding and dividing forms were sometimes seen among them.The main alterations found in the infected cells were: increased ribosome content, dilation of the perinuclear space, degeneration of mitochondria and chloroplasts, and cytoplasmic vacuolation. Many cells appeared completely disrupted and their content was replaced by a great number of pleomorphic mycoplasma.This investigation was supported by a grant of Consiglio Nazionale delle Ricerche, Rome.     

Role of tyrosine residues in cytoplasmic aspartate aminotransferase from beef kidney

Summary Cytoplasmic aspartate aminotransferase from beef kindney loses 25% of its activity on nitration with tetranitromethane while the apoenzyme about 95%. In the holoenzyme 0.5 tyrosine residue and 1.0 tyrosine residue in the apoenzyme are nitrated per enzyme protomer. In addition 1 cysteine residue per protomer is oxidized in both. The presence of substrates,-ketoglutarate and glutamate, both at ten times their K_m values, does not change these results. Mercaptoethanol does not affect the residual activity of either the nitrated holo or apoenzyme. Dithionite abolishes the activity of the nitrated holoenzyme by reducing the coenzyme moiety. It has no effect on the native holoenzyme or on either the native or nitroapoenzyme.This work is part of a program supported by a grant from the Consiglio Nazionale delle Ricerche.     

Parafollicular cells of rabbit thyroid store both calcitonin and somatostatin and resemble gut D cells ultrastructurally

Summary Both calcitonin and somatostatin have been detected immunohistochemically in rabbit parafollicular cells; only calcitonin has been found in the same cells of the dog, guinea-pig and man. Large amounts of a peptide radioimmunochemically identical with synthetic somatostatin have been detected in extracts of rabbit thyroid. The ultrastructural and staining features of rabbit parafollicular cells differ from those of parafollicular cells in other species, while resembling in part those of somatostatin D cells scattered in the rabbit stomach.Supported in part by grants from the Italian Ministero della Pubblica Istruzione and Consiglio Nazionale delle Ricerche     

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.