Release of endonucleobiotic bacteria Holospora bacillata and Holospora curvata from the macronucleus of their host cells Paramecium woodruffi and Paramecium calkinsi

For 3 of 9 species of Holospora (H. caryophila, H. bacillata and H. curvata) which infect the nuclei of different species of Paramecium the mechanism of release of the infectious forms from the nucleus through the connecting piece (a bridge between the two daughter macronuclei) which occurs in infected cell lines quite often has not been observed. The possibility for the bacteria to leave the infected nucleus is to pass through the perinuclear space of the infected nucleus into the cytoplasm. This is described in this study for H. bacillata and H. curvata.