Viscoelastic studies on Tetrahymena macronuclear DNA.

Electron-microscopic observations on the macronuclear development of Stylonychia mytilus and Tetrahymena pyriformis (Ciliophora-Protozoa).

This report describes an ultrastructural investigation of macronuclear development following conjugation in Stylonycltia mytilus (a spirotrichous ciliate) and Tetrahymena pyriformis (a holotrichous ciliate). In S. mytilus, polytene chromosomes are formed in the young macronucleus (macronuclear Anlage). They are subsequently broken between the bands by 'membranous' partitions; the assembly of th...

Mean macronuclear DNA contents are variable in the ciliate Tetrahymena.

Using cytophotometry the mean macronuclear DNA content of the ciliate Tetrahymena was found to be variable in two cell lines examined. While environmental changes (different culture fluids, temperature shifts) influence the mean DNA content of at least one of the two cell lines, spontaneous changes of the means are observed in both lines. The mean DNA contents of cultures maintained permanently...

[6n]methyl Adenine in the Nuclear Dna of a Eucaryote, Tetrahymena Pyriformis

DNA isolated from macronuclei of the ciliate, Tetrahymena pyriformis, has been found to contain [(6)N]methyl adenine (MeAde); this represents the first clear demonstration of significant amounts of MeAde in the DNA of a eucaryote. The amounts of macronuclear MeAde differed slightly between different strains of Tetrahymena, with approximately 0.65-0.80% of the adenine bases being methylated. The...

Replication and Functions of Macronuclear Dna in Synchronously Growing Populations of Tetrahymena Pyriformis

Chromodomain protein Tcd1 is required for macronuclear genome rearrangement and repair in Tetrahymena

The survival of an organism's progeny depends on the maintenance of its genome. Programmed DNA rearrangement and repair in Tetrahymena occur during the differentiation of the developing somatic macronuclear genome from the germ line micronuclear genome. Tetrahymena chromodomain protein (Tcd1) exhibited dynamic localization from the parental to the developing macronuclei. In the developing macro...