The symbiotic intestinal ciliates and the evolution of their hosts

• Published in: European journal of protistology Vol. 50; no. 2; pp. 166 - 173
• Main Authors: Moon-van der Staay, Seung Yeo, van der Staay, Georg W.M., Michalowski, Tadeusz, Jouany, Jean-Pierre, Pristas, Peter, Javorský, Peter, Kišidayová, Svetlana, Varadyova, Zora, McEwan, Neil R., Newbold, C. Jamie, van Alen, Theo, de Graaf, Rob, Schmid, Markus, Huynen, Martijn A., Hackstein, Johannes H.P.
• Format: Journal Article
• Language: English
• Published: Munich Elsevier GmbH 01.04.2014; Elsevier
• Subjects: 18S rDNA; Animal, plant and microbial ecology; Animals; Biodiversity; Biological and medical sciences; Biological evolution; Caecum/colon; Ciliates; Ciliophora - classification; Ciliophora - genetics; Ciliophora - physiology; Community analysis; Computer Science; Elephantidae; Elephas maximus; Entodiniomorphida; Equus caballus; Equus quagga; Feces - parasitology; Fundamental and applied biological sciences. Psychology; Gastro-intestinal tract; Genetics of eukaryotes. Biological and molecular evolution; Humanities and Social Sciences; Intestines - parasitology; Life Sciences; Microbial ecology; Normal microflora of man and animals. Rumen; Phylogeny; Protozoa; RNA, Ribosomal, 18S - genetics; Rumen; Rumen - parasitology; Ruminantia; Ruminants - classification; Ruminants - genetics; Ruminants - parasitology; Systematics. Geographical distribution. Morphology. Cytology; Ciliates; Rumen; 18S rDNA; Community analysis; Gastro-intestinal tract; Caecum/colon; Equus caballus; Biological evolution; Ribosomal DNA; Colon; Ungulata; Community structure; Proboscidea; Protozoa; Gut; Loxodonta africana; Host; Coevolution; Symbiont; Vertebrata; Mammalia; Animal community; Elephas maximus; Ciliata; Perissodactyla; BACTERIA; PHYLOGENETIC ANALYSIS; SHEEP RUMEN; CILIOPHORA; 18S RDNA SEQUENCES; ELEPHANTS; ENTODINIOMORPHIDA; ORIGINS; PROTOZOA; DIVERSITY
• ISSN: 0932-4739; 1618-0429
• DOI: 10.1016/j.ejop.2014.01.004

The evolution of sophisticated differentiations of the gastro-intestinal tract enabled herbivorous mammals to digest dietary cellulose and hemicellulose with the aid of a complex anaerobic microbiota. Distinctive symbiotic ciliates, which are unique to this habitat, are the largest representatives of this microbial community. Analyses of a total of 484 different 18S rRNA genes show that extremely complex, but related ciliate communities can occur in the rumen of cattle, sheep, goats and red deer (301 sequences). The communities in the hindgut of equids (Equus caballus, Equus quagga), and elephants (Elephas maximus, Loxodonta africanus; 162 sequences), which are clearly distinct from the ruminant ciliate biota, exhibit a much higher diversity than anticipated on the basis of their morphology. All these ciliates from the gastro-intestinal tract constitute a monophyletic group, which consists of two major taxa, i.e. Vestibuliferida and Entodiniomorphida. The ciliates from the evolutionarily older hindgut fermenters exhibit a clustering that is specific for higher taxa of their hosts, as extant species of horse and zebra on the one hand, and Africa and Indian elephant on the other hand, share related ciliates. The evolutionary younger ruminants altogether share the various entodiniomorphs and the vestibuliferids from ruminants.