Tolnai Márton -Vas-Zoltán Péter (szerk.): Guide to research and scholarship in Hungary 1. (Budapest, 1988)

Part One: Papers Related to Individual Fields of Science

biochemical methods is the nitrogen fixation in Rhizobium. The genetic regulation of the plant-bacterium interaction is jointly under study with the Max Planck Institut für Pflanzenzüchtung in the Federal Republic of Germany. The genetic map of Rhizobium meliloti (with 45 marker loci) has been constructed using a special conjugative plasmid and the 16-3 transducing phage. The restriction site pattern of the latter has also been mapped. The genes responsible for the fixation of nitrogen (nif genes) have been isolated, one of them (nitrogenase reductase) also sequenced together with its promoter (BRC-HAS [13]; Department of Genetics, József Attila University, Szeged [173]). A basically new method of bacterial gene transfer has been developed by means of bacterial protoplast fusion—a technique generally used in eukaryotic cells (BRC­­HAS [13]), while the bacterial transformation has been extended to the eukaryotic moulds (Neurospora crassa) '(Institute of Biology, University Medical School, Debrecen [491]). The latter became historically the first reproducible eukaryotic transformation system. Several other molecular genetic studies "are in progress in various laboratories. The processes of mutation and repair are being investigated in mammalian cell cultures and in Drosophila. The results are applied in the improvement of mutagen testing methods (BRC-HAS [13]; Department of Genetics, Eötvös Loránd University [75]). The molecular basis of bacterial sporulation is being studied in Debrecen at the Institute of Biology, University Medical School [491]. These latter topics carry us over to the next level of organization, the cell. CELL BIOLOGY Various biological problems of unicellular organisms (both pro- and eukaryotic) are studied in many laboratories throughout the country. A recent compilation identifies 22 institutions devoting some research to microbiology. (These are partly of applied character.) Two of these should be mentioned: the Departments of Microbiology of József Attila University, Szeged [1*70], and Eötvös'Loránd University, Budapest [76]. The former is a well-known center for yeast biology, where success has been-achieved in fusing yeast protoplast carrying suitable nuclear and/or mitochondrial genetic markers. In this manner combinations were made which were impossible through sexual crosses. The Budapest Department of Microbiology [76] investigates popula­tions of bacteria in connection with ecological problems of the soil, water, mud, etc. Methods of numerical taxonomy are applied in order to obtain a better knowledge of inter- and intraspecific similarities of in situ isolated bacterial strains. The ultrastructural features of diverse cell types are also studied. The peculiar membrane interconnections and other characteristics of the plant cell are thoroughly investigated in the Department of Plant Anatomy, Eötvös Loránd University, Budapest [78]. On the other hand, the fine structure of the eukaryotic chromosomes has long been studied at the Institute of Genetics, BRC-HAS, Szeged [13]. Metaphase chromosomes have been isolated from synchronized wheat protoplast cultures. The chromosomes were treated in various ways (e.g., histones depleted) in order to reveal their structural organization. Very sophisticated work on somatic cell genetics is in progress at the Institute of 91

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