The blue-green alga agmenellum quadruplicatum contains covalently closed DNA circles

Cell. 1976 Dec;9(4 Pt 1):551-7. doi: 10.1016/0092-8674(76)90037-4.

Abstract

This paper reports the first direct visualization of covalently closed, circular DNA from a blue-green alga. Agmenellum quadruplicatum lysates, fractionated on CsCl-ethidium bromide density gradients, yield a minor band of covalently closed DNA circles which we have analyzed by electron microscopy and agarose gel electrophoresis. The DNA consists of a number of a discrete classes of DNA circles ranging in molecular weight from 3 X 10(6) daltons to 65-80 X 10(6) daltons. The function of these circles is at present entirely unknown.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Centrifugation, Density Gradient
  • Cyanobacteria / analysis*
  • Cyanobacteria / growth & development
  • DNA, Circular*
  • Electrophoresis, Agar Gel
  • Molecular Weight
  • Nucleic Acid Conformation*

Substances

  • DNA, Circular