Morphological diversity of the micronuclei in Paramecium

Morphological analysis of the micronuclei in 51 stocks of 10 Paramecium species was carried out to examine the diversity of the nuclear morphology in these organisms. Instead of the two general structural types of micronuclei which are well-known in the literature ('caudatum' and 'aurelia'), 4 types of nuclei are proposed. They are the 'vesicular' type (P. polycaryum, P. arcticum, P. aurelia, P. multimicronucleatum), the 'endosomal' type (P. calkinsi, P. woodruffi, P. duboscqui), the 'chromosomal' type (P. jenningsi, P. wichtermani) and the 'compact' type (3 varieties) - P. caudatum (a), P. bursaria (b) and P. putrinum (c)