[A cytophotometric study of the amount of DNA in the macro- and micronuclei of the infusorian Nyctotherus cordiformis from the gut of tadpoles and juveniles of the common frog].

The investigations of DNA amounts in the nuclei of the ciliate Nyctotherus cordiformis was continued. The measured ciliates were collected from guts of tadpoles and the most small frogs just from the water. The DNA content was measured (in arbitrary units--a.u.) in the nuclei of cysts, precysts, vegetative ciliates and small frogs. This paper is the second part of the investigation. The first part dealt with DNA amounts of the nuclei of the vegetative ciliates tested in spring, autumn and winter. The amount of the Feulgen-DNA complex was measured with a two-wave microcytophotometer MCFU-1. The average content of the DNA ranged from 1.7 +/- 2 a.u. in the Mi of cysts to 2.6 +/- 0.1 a.u. in the Mi of the youngest frogs. The DNA content of the Ma ranged from 275 +/- 21 a.u. in cysts to 479 +/- 25 a.u. in vegetative ciliates. The DNA content in presynthetic Mi (G1) is supposed to be approximately 1.3 and approximately 2.6 a.u. in postsynthetic (G2) Mi. Using nuclei of erythrocytes of Rana temporaria as internal standard, the DNA content of a 2 c Mi from tadpoles of N. cordiformis is supposed to amount to 0.57 pg or approximately 350 gDa. The DNA amount in Ma of N. cordiformis is at average 140-220 times as that of Mi.