title: Minicircular DNA having sequence homologies with chloroplast DNA in a bleached mutant of Euglena gracilis.
abstract: Chloroplast DNA was isolated from total cellular DNA of a bleached mutant of Euglena gracilis (Y3BUD) by enrichment of the light component (p = 1.686) by repeated CsCl equilibrium centrifugations. Electron microscope visualization of this DNA showed minicircular DNA molecules in addition to large circular molecules (42 pm) identical to wild type chloroplast DNA. They were heterogenous in size and their contour lengths ranged from 0.8 to 8.5 μm. Fractionnation by agarose gel electrophoresis gave several discrete bands. Some of them hybridized with pure chloroplast DNA and with several cloned chloroplast DNA fragments, particularly to ribosomal fragments, while others did not show homology with chloroplast DNA being probably of extrachloroplatic origin.
authors.affiliation: Département de Biologie Générale, Université Claude Bernard Lyon I, 43 Boulevard du 11 Novembre 1918, F-69622, Villeurbanne Cedex, France.
authors.forename: P
authors.initials: P
authors.lastname: Heizmann
authors.forename: P
authors.initials: P
authors.lastname: Ravel-Chapuis
authors.forename: V
authors.initials: V
authors.lastname: Nigon