Probleme Der Biologischen Reduplikation: Funktionelle Und Morphologische Organisation Der Zelle

ISBN-13: 9783540036388 / Niemiecki / Miękka / 1966 / 412 str.

Peter Sitte

Opis

Lampbrush chromosomes which are chromosomes in meiotic pro phase with laterally projecting loops, have been observed in oocyte nuclei of several vertebrate, some invertebrate species, and in spermato cyte nuclei of Drosophila species. Especially large lampbrush chromo somes occur in oocytes of the urodele Amphibia and in spermatocyte nuclei of Drosophila hydei and some other species belonging to the hyde i subgroup. In Amphibia the premeiotic chromosomes show a chromomeric organization and a pair of lateral loops projects from each chromomere. Often the loops show a thin axis and a matrix consisting of many radial projecting fibers attached to it. Moreover, the loops are often asymmetric. One of the insertions of the loops in the chromomere may have long fibers and as one follows around the loops from this end, the projecting fibers become progressively shorter and then disappear so that the second end of the loops is bare of fibers. Some of the large loops show morphological peculiarities in length or thickness, or in the nature of their matrix. These characters are constant and locus specific and have allowed to establish loop maps for the genome of several Amphibian species. Lamp brush chromosomes are highly extensible. Breakages after stretching beyond the elastic limits occur always transversely accross chromo meres in such a way that a pair of lateral loops span the break. The axis of the loops appears to contain DNA and there is evidence that the DNA con sists of only one double helix in each loop."

Spis treści

Probleme der Reduplikation von Nucleinsäuren (Problems in reduplication of nucleic acids).- Diskussion.- The duplication of chromosomes.- Discussion.- Funktionelle und strukturelle Organisation der Lampenbürsten-chromosomen (Function and structure of lamp-brush chromosomes).- Diskussion.- Lokale DNS-Replikation in Riesenchromosomen (Reduplication of DNA in giant chromosomes).- Diskussion.- Beobachtungen zur Vermehrung und Funktion nucleolärer Strukturen (Observations on multiplication and function of nucleolar structures).- Diskussion.- Morphological aspects of normal and abnormal mitosis.- Discussion.- Enzymatische Aspekte der Mitose (Enzymatic aspects of mitosis).- Diskussion.- Analyse des Zellcyclus durch Eingriffe in die Makromolekül-Biosynthese (Analysis of the cell cycle by interference with macromolecular biosynthesis).- Diskussion.- Beobachtung von Vorgängen im Submikroskopischen — Möglichkeiten und Grenzen (Possibilities for the recognition of events at a submicroscopic level).- Diskussion.- Morphologie und Morphogenese der Plastiden (Chloroplasten) (Morphology and morphogenesis of plastids).- Diskussion.- Über die Vermehrung von Plastiden und Mitochondrien während der Oogenese von Sphaerocarpus (The multiplication of plastids and mitochondria during oogenesis of Sphaerocarpus).- Diskussion.- Nucleinsäuren und Proteinsynthese in Plastiden (Nucleic acids and protein synthesis in plastids).- Diskussion.- Die Plastiden als Erbträger (Plastids as carriers of genetic information).- Diskussion.- Morphologische Aspekte der Mitochondrienvermehrung (Morphological aspects of the multiplication of mitochondria).- Diskussion.- The biogenesis of mitochondria in Neurospora — A summary of present findings.- Mitochondrien als Träger genetischer Information (Mitochondria as carriers of genetic information).- Diskussion.- Proposals concerning replication of the Golgi apparatus.- Discussion.- Organellen-Reduplikation und Zellkompartimentierung (Reduplication of organelles and the problem of compartmentation of the cell).- Diskussion.- Grundprinzipien der Reduplikation komplexer Systeme (Principles of reduplication of complex systems).- Diskussion.

O autorze

Peter Sitte, geb. 1929 in Innsbruck. Studium der Biologie, Chemie, Experimentalphysik und Philosophie in Innsbruck. 1960 Übernahme eines Extraordinariats an der Universität Heidelberg. 1966 Ordinarius für Zellbiologie in Freiburg. Forschungsschwerpunkte: Zellbiologie u. -evolution, Feinstrukturforschung, Biosymmetrie und -ästhetik, philosophische und gesellschaftliche Aspekte der Biologie.