Induced regeneration of plants in tissue cultures ofBrassica oleracea

Résumé Dans les cultures de tissus repiqués de Chou moellier une néoformation de plantes entières se produit en conséquance de l'exclusion du 2,4-D du milien de culture.

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We thank Miss A.temberová and Mrs. M.Paldusová for valuable technical assistance.     

The effects of radiation on enzymes in tissue cultures

Riassunto Colture primarie di rene di scimmia (M. rhesus) presentano, dopo l'irradiazione, un aumento nell'attività della fosfatasi alcalina, mentre l'attività della fosfatasi acida non risulta modificata.     

The cellular sources of antibodies in diffusion chamber cultures of alveolar exudates

Zusammenfassung Alveolarexsudatzellen von Kaninchen wurden zusammen mit Schaferythrozyten in Diffusionskammern gebracht und diese in neugeborene Kaninchen implantiert. Antikörperbildende Zellen wurden in den Diffusionskammern und im Omentum der Rezipienten festgestellt.     

Ethylene effects on tissue cultures ofNicotiana tabacum

Riassunto Si è studiato l'effetto dell'etilene su culture di cellule diNicotiana tabacum, in vitro. I risultati ottunuti mostrano che le auxine in presenza di etilene inibiscono la crescita di frammenti di callus, e che tale inibizione viene rimossa dalla kinetina.

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The author thanks Prof.G. Montalenti and Prof.G. Morpurgo for discussions andG. Conti for excellent technical assistance.     

Actions of interferon in tissue cultures harboring mouse leukemia virus

Zusammenfassung Das Virus der vesikulären Stomatitis verursacht Zellverschmelzung und Syncytienbildung in mit Mäuse-Leukämie-Virus infizierten Gewebskulturen. Interferon konnte diese Zellzerstörung in der Kultur nicht verhindern.

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This work was supported by U.S.P.H.S. research grant No. CA-7923 and award No. K3-CA-16747.     

Slice cultures of cerebellar,hippocampal and hypothalamic tissue

Summary Cerebellar, hippocampal and hypothalamic slices prepared from newborn and 7-day-old rats were cultured by means of the roller-tube technique. Identification of cells was made easier by the fact that at least part of the characteristic cytoarchitecture of the tissue was preserved in vitro. Cerebellar Purkinje cells and neurones of the deep cerebellar nuclei were recognized on the basis of their size, their location within the culture and their dendritic arborization. Pyramidal cells of all hippocampal subfields displayed their characteristic basal and apical dendritic trees with numerous spinous processes. Hippocampal granule cells gave rise to a monopolar dendritic arbor; their axons terminated in the dentate hilus and CA3 region. Golgi-like immuniperoxidase staining allowed localization of groups of neurophysin-positive neurones in slices prepared from the anterior hypothalamus. These neurones, bilaterally bordering the third ventricle, usually displayed a simple dendritic arborization and fine beaded axons.—Cultivation of brain slices prepared from young rats offers particular advantages in that the cultured cells are organized in an organotypic monolayer and individual living neurones may be directly visualized.Acknowledgments. I would like to thank Dr J. Zimmer and Dr M. Sofroniew for their valuable help with the Timms and immunoperoxidase staining techniques and Mr R. Schlichter and L. Wohlfart for illustrating the culture procedure. The excellent technical assistance of Ms L. Rietschin and E. Hoffmann is gratefully acknowledged.     

Chemical communication in invertebrates

Conclusions In conclusion, olfactory pheromones are widespread in nature and control many fundamental aspects of an insect's life. Detailed behavioral observations in the field and laboratory indicate the great complexity of most pheromone communication systems. The preliminary electrophysiological experiments on single olfactory receptor neurons that we have described here, point toward the possibility of unraveling the basic physiological mechanisms underlying these behavioral complexities. This information is directly applicable to many problem areas in chemoreception and could provide a base for the rational use of pheromones in the control of insect pests. *** DIRECT SUPPORT *** A2025171 00003     

Vegetative propagation of the cactusMamillaria woodsii craig through tissue cultures

Summary A new method of clonal multiplication is described in a representative from the Cactaceae family, which offers wide experimental and horticultural applications.