A new interpretation of stomatogenesis in a peritrich ciliate: using Campanella umbellaria as a model system.
ABSTRACT The process of stomatogenesis in peritrich ciliates is still incompletely understood. Previous studies on the stomatogenesis of four species of peritrichs, Telotrochidium sp., Carchesium polypinum, Opercularia coarctata, and Astylozoon pyriforme conflict with one another in some cases and omit details of events in others. We described the entire process of stomatogenesis in the peritrich ciliate Campanella umbellaria (C. umbellaria) using an improved method of staining with protargol. Our results disagree with some previous studies with regard to the formation of some rudimentary structures, reorganization of the parental haplokinety, formation of new germinal rows, and separation of daughter oral complexes. The pattern of stomatogenesis characteristic of peritrichs is compared to the stomatogenetic patterns of three other oligohymenophorean subclasses and a hypothesis about the evolution of stomatogenesis in the class Oligohymenophorea is offered. Details of stomatogenesis need to be described and verified in a greater variety of peritrichs to clarify possible differences between taxa and make it possible to relate stomatogenesis to evolution within the subclass Peritrichia. Ultrastructural studies are the next step in description of morphogenetic processes in peritrichs, and characteristics of C. umbellaria make it a useful model for this work.
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ABSTRACT: The stomatogenesis of peritrich ciliates is an important developmental process but has been studied relatively little for such a large, diverse taxon. Complex oral structures and an inability of staining techniques to reveal them clearly have been the major factors hindering investigation of this process. In the present study, an improved method of staining with protargol was used to investigate the entire process of stomatogenesis in a large, colonial species of peritrich, Pseudepistylis songi, and to compare it to descriptions of stomatogenesis in several other species. We found that P. songi and other peritrichs have the same general type of ophryobuccokinetal stomatogenesis, with the parental oral complex being inherited by one daughter and the new oral complex by the other daughter; however, some differences between individual taxa appear to have arisen in the course of evolution. Reorganization of the entire germinal kinety (Gk) to form the germinal anlage may be plesiomorphic, with restriction of reorganization to its abstomal part being apomorphic. Development of the entire new haplokinety of one daughter cell (2Hk) from the germinal band or its homologue also appears to be plesiomorphic, with development of peristomial and infundibular parts of 2Hk from separate rudiments being apomorphic. Furthermore, development of the new Gk of the parental oral complex (1Gk) from the entire infundibular part of the parental haplokinety (1Hk) may be plesiomorphic, and development from just the abstomal part may be apomorphic. Finally, development of the Gk of the new oral complex (2Gk) from residual kinetosomes of the germinal band appears to be plesiomorphic.Journal of Eukaryotic Microbiology 06/2012; 59(4):300-24. · 2.16 Impact Factor
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ABSTRACT: A limnetic peritrichous ciliate, Epistylis plicatilis Ehrenberg, 1831, was collected from a freshwater ditch beside Moshan Hill, Wuhan, China. Its morphology, infraciliature, and morphogenesis were investigated based on specimens examined in vivo, following staining with protargol and by scanning electron microscopy. The characteristics of the Wuhan population of E. plicatilis are as follows: 1) colonial, each colony typically comprising 30–50 individuals, with a dichotomously branched, noncontractile stalk; 2) fully expanded zooids measure 90–155 × 30–50 µm in vivo; 3) a series of 6 or 7 conspicuous folds appear in the posterior region of the zooid when it contracts; 4) single horseshoe-shaped macronucleus oriented transversely; 5) single contractile vacuole located in peristomial region on dorsal wall of infundibulum; 6) myoneme system comprises 20–24 longitudinal fibers, peristomial disk fibers as a wreath-like net and peristomial ring fibers; 7) narrowly spaced transverse striations on the surface of the body; 8) infundibular polykineties 1 and 2 are three-rowed, infundibular polykinety 3 is two-rowed; and 9) stomatogenesis is of the buccokinetal type; in the new oral apparatus, infundibular polykineties 2 and 3, the haplokinety, and the germinal kinety all originate from the germinal kinety of the parental oral apparatus whereas the polykinety and infundibular polykinety 1 originate from the parental haplokinety. An improved diagnosis of E. plicatilis is supplied. J. Morphol., 2014. © 2014 Wiley Periodicals, Inc.Journal of Morphology 03/2014; · 1.60 Impact Factor