Bardele Christian F, Schultheiß Sigrid, Lynn Denis H, Wright André-Denis G, Dominguez-Bello Maria Gloria, Obispo Nestor E
Department of Evolution and Ecology, University Tübingen, Tübingen, Germany.
Department of Integrative Biology, University of Guelph, Guelph, ON N1G 2W1, Canada.
Protist. 2017 Jul;168(3):335-351. doi: 10.1016/j.protis.2017.02.002. Epub 2017 Mar 7.
The hoatzin is the only known avian species that has evolved a foregut fermentation system similar to that of ruminant animals. Due to the closeness of the bird's fermentation chamber, the crop, to the bird's beak it exudes an unpleasant odour; therefore, the hoatzin is called the "cow among the birds". In addition to Eubacteria and Archaea, responsible for digestion of the vegetation they consume, the bird's crop contains a holotrich ciliate, described here for the first time in detail. Cytological staining of this isotrichid-like ciliate with the Chatton-Lwoff and Protargol staining procedures, as well as SEM and TEM, justified the establishment of the new genus Aviisotricha n. gen. with its new type species Aviisotricha hoazini n. gen., n. sp.. Phylogenetic analyses of a portion of the small subunit rRNA gene supported the taxonomic placement of this new genus and species in the family Isotrichidae. Aviisotricha is compared with Balantidium, Dasytricha and Isotricha with special reference to their dorsal brushes, which show similarity to the paralabial organelle of the Entodiniomorphida. The possible phylogenetic origin of Aviisotricha is discussed and a taxonomic revision of the family Isotrichidae is given.
麝雉是已知唯一进化出类似于反刍动物前肠发酵系统的鸟类物种。由于这种鸟的发酵腔（嗉囊）离其喙很近，会散发出一股难闻的气味；因此，麝雉被称为“鸟类中的奶牛”。除了负责消化其所食用植被的真细菌和古细菌外，这种鸟的嗉囊中还含有一种全毛纤毛虫，本文首次对其进行了详细描述。用Chatton-Lwoff染色法和普罗他哥尔染色法对这种类等毛纤毛虫进行细胞学染色，以及扫描电镜和透射电镜观察，证明了新属Aviisotricha n. gen. 及其新物种Aviisotricha hoazini n. gen., n. sp. 的建立。对小亚基rRNA基因的一部分进行系统发育分析，支持了这个新属和新物种在等毛科中的分类地位。将Aviisotricha与小袋纤毛虫属、毛滴虫属和等毛属进行了比较，特别提到了它们的背刷，其与内毛目动物的唇旁细胞器相似。讨论了Aviisotricha可能的系统发育起源，并对等毛科进行了分类修订。
