Extranuclear DNA and the Endosymbionts of Paramecium aurelia

Kappa and other endosymbionts in Paramecium aurelia.

“…The 138 mu has been found to have glutamate dehydrogenase, malate dehydrogenase, and isocitrate dehydrogenase, all with different Michaelis constants from those present in the host paramecia (41).…”

The Size and Structure of the DNA Genome of Symbiont Xenosome Particles in the Ciliate Parauronema acutum

“…Bacteriophage T4 contains sufficient DNA to code for about 160 proteins. Gibson et al (1971) reported values of 3.3 x lo9 and 3.4 x lo9 daltons for the kinetic complexities of mu endosymbionts of Paramecium aurelia stocks 551 and 540, respectively. Because their paper did not contain details of the conditions of their experiments it is not possible to interpret their results meaningfully.…”

Isolation of intracellular symbiotes by immune lysis of flagellate protozoa and characterization of their DNA.

“…The genome complexity of symbiotes in B. culicis was determined in the present study to be 6.7 • 109 daltons. Parallel studies have been made recently in Paramecium endosymbiotes lambda and mu, whose genome complexities are of the order of 108 and l0 P daltons, respectively (15,53). A more recent report on endosymbiotic "xenosomes" of marine ciliates indicates a genome complexity similar to that of lambda (54).…”

“…Average values for the genome complexity of DNA's of B. culicis were calculated from rcnaturation rate constants using the procedure and formulae of Wetmur and Davidson(67). Values for genome complexities of other DNA's were obtained from: mu 540 and mu 551(15), lambda 299 (53), E. coli(67), and M. fermentans (PG 18) (2).…”