Main Content

The World of Protozoa, Rotifera, Nematoda and Oligochaeta

Ref ID : 7581

Maria Jerka-Dziadosz; Ultrastructural Study on Development of the Hypotrich Ciliate Paraurostyla weissei III. Formation of Preoral membranelles and an Essay on Comparative Morphogenis. Protistologica XVII(1):83-97, 1981

Reprint

In File

Notes

The assembly and patterning of the undulating membranes (UM) in hypotrich ciliate Paraurostyla weissei were studied using light and transmission electron microscopy. The UM complex is composed of two preoral membranelles: inner (IPM) and outer (OPM) ones. The UM primordium originates as an anarchic field of kinetosomes which then asssemble into pairs and produce specific accessory microtubular ribbons. The pairs line up with homogenous orientation forming a longitudinal row of paired kinetosomes with all postciliary ribbons directed toward the cell left. The single preoral membranelle then differentiate from the left components of pairs, the outer membranelle individuate by packing up of the right components of pairs and loosely dispersed kinetosomes from the right side of the primordium. The two membranelles then split longitudinally and are separated by a cytoplasmic fold. Second round of kinetosome proliferation was not observed in the UM primordium. The pattern of differentiation of preoral membranelles in P. weissei differs significantly from differentiation of the AZM as well as from differentiation of the ventral ciliary streaks. The results of observations are discussed in relation to specificity of kinetosomal pairs in different kind of primordia.