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Plagiopyla

About: Plagiopyla is a(n) research topic. Over the lifetime, 4 publication(s) have been published within this topic receiving 84 citation(s).

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Journal ArticleDOI
TL;DR: Ciliates with methanogens produced CH4 under microaerobic conditions due to their ability to maintain an anoxic intracellular environment at low external oxygen tensions andoretical considerations suggest that hydrogen transfer is significant to the metabolism of larger anaerobic ciliates.
Abstract: Rates of methane production by three anaerobic ciliates containing symbiotic methanogens (the marine Metopus contortus and Plagiopyla frontata, and the limnic Metopus palaeformis) were quantified. Hydrogen production by normal (containing active symbionts), aposymbiotic and BES-treated cells was also measured in the case of the marine species. Methanogenesis was closely coupled to host metabolism and growth; at maximum ciliate growth rates (20°C) each methanogen produced about 1 fmol CH4 per hour corresponding to about 7, 4 and 0.35 pmol per ciliate per hour for M. contortus, P. frontata and M. palaeformis, respectively. Normal cells produced traces of H2. Hydrogen production by BES-treated or aposymbiotic cells accounted for 75 and 45% of the methane production of normal M. contortus and P. frontata cells, respectively. However, it is possible that hydrogen production was partly inhibited in the absence of methanogens. Theoretical considerations suggest that hydrogen transfer is significant to the metabolism of larger anaerobic ciliates. Ciliates with methanogens produced CH4 under microaerobic conditions due to their ability to maintain an anoxic intracellular environment at low external oxygen tensions. Methanogenesis was still detectable at a pO2 of 0.63 kPa (3 %atm sat).

60 citations

Journal ArticleDOI
TL;DR: The evidence indicates that E. balteatus is a facultative commensal, which is perhaps now in the process of acquiring the endozoic habit, and the usual macronuclear reorganization which occurs in Euplotes and its near relatives is shown.
Abstract: Of 165 sea urchins (Strongylocentrotus drobachiensis) examined in the Mt. Desert Island region, 41 harbored the intestinal ciliate Plagiopyla minuta in considerable numbers. Division in this ciliate is clean; i.e. it is not accompanied by the visible elimination of macronuclear material. Long periods (probably several weeks) of vegetative life appear to alternate with brief periods of intense divisional activity in P. minuta. Twenty-five of these same urchins also contained in their digestive tracts a species of Euplotes which was identified as E. balteatus. This hypotrich was also found commonly in the region as a free-living organism. Dividing specimens were found regularly in the urchin, and such specimens showed the usual macronuclear reorganization which occurs in Euplotes and its near relatives. The evidence indicates that E. balteatus is a facultative commensal, which is perhaps now in the process of acquiring the endozoic habit.

13 citations

Journal ArticleDOI
TL;DR: Both Lechriopyla mystax Lynch and Plagiopyla minula Powers, 1933 contain hydrogenosome-methanogen assemblages similar to those reported for other plagiopylid ciliates, which probably plays a significant role in exploitation of the methanogens by the host ciliate.
Abstract: . Lechriopyla mystax Lynch, 1930 and Plagiopyla minula Powers, 1933 contain hydrogenosome-methanogen assemblages similar to those reported for other plagiopylid ciliates. These assemblages are stacks of elongate ovoid hydrogenosomes alternating with methanogens; these stacks are surrounded by cisternae of the rough endoplasmic reticulum that are often accompanied by Golgi complexes. The individual methanogens in the larger ciliate, L. mystax, are about four times the volume of those in the smaller ciliate, P. minuta, but both ciliates appear to contain Gram-negative methanococcoid bacteria, possibly Methanoplanus sp. The endoplasmic reticulum-Golgi complex probably plays a significant role in exploitation of the methanogens by the host ciliate.

11 citations

Journal ArticleDOI
Abstract: The morphology and molecular phylogeny of Plagiopyla ovata Kahl, 1931, a poorly known anaerobic ciliate, were investigated based on a population isolated from sand samples collected from the Yellow Sea coast at Qingdao, PR China. Details of the oral ciliature are documented for the first time to our knowledge and an improved species diagnosis is given. The small subunit ribosomal RNA (SSU rRNA) gene was newly sequenced and phylogenetic analyses revealed that P. ovata clusters within the monophyletic family Plagiopylidae. However, evolutionary relationships within both the family Plagiopylidae and the genus Plagiopyla remain obscure owing to undersampling, the lack of sequence data from known species and low nodal support or unstable topologies in gene trees. A key to the identification of the species of the genus Plagiopyla with validly published names is also supplied.
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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20211
19922
19541