Osipov D V, Skoblo I I, Rautian M S
Tsitologiia. 1975 Jan;17(1):95-8.
Particles of a newly described endosymbiont of Paramecium caudatum, clone M-115, here referred to as iota--particles, are Gram--negative bacteria. The symbionts are only present within macronuclei and not in the cytoplasm or in the micronuclei. The cells of clone M-115 iota do not display any killer-effect when mixed with "clean" cultures of Paramecia. In life cycle of the symbiont, there is an alternation of two morphological forms: a spindle-shaped form 2.0--2.5 microns long and a rod-shaped form -- about 18 microns long. The data obtained revealed a high ability to infect cell of "clean" clones of P. caudatum with iota-particles. The antagonistic relationships between two different species of endonucleosymbionts: iota- and omega-particles, are detected. The revealed biological features of iota can be used for studying the mechanisms of nuclear differentiation in ciliates.
新描述的尾草履虫克隆M-115的一种内共生体颗粒，这里称为ι颗粒，是革兰氏阴性细菌。这种共生体仅存在于大核内，而不存在于细胞质或小核中。当克隆M-115的ι颗粒细胞与“纯净”的草履虫培养物混合时，不会表现出任何杀伤作用。在共生体的生命周期中，有两种形态形式交替出现：一种是长2.0 - 2.5微米的纺锤形，另一种是长约18微米的杆状。所获得的数据表明，ι颗粒具有很高的感染尾草履虫“纯净”克隆细胞的能力。检测到两种不同种类的核内共生体（ι颗粒和ω颗粒）之间的拮抗关系。所揭示的ι颗粒的生物学特性可用于研究纤毛虫核分化的机制。
