Morphology and molecular phylogeny of Oxytricha seokmoensis sp. nov. (Hypotrichia: Oxytrichidae), with notes on its morphogenesis

초록

A new hypotrichous ciliate, Oxytricha seokmoensis sp. nov., was discovered in a soil from a forest in South Korea and described based on the observations of living and stained specimens. In addition, phylogenetic analyses were performed using the small subunit ribosomal RNA (18S rRNA) gene sequence, Morphologically, the new species is similar to the O granulifera-complex in terms of ciliary structure and arrangement of cortical granules, but dorsal kinetics 3 and 4 (not completely separated vs. separated) and macronuclear nodules in the cyst (separated vs. fused) differ. Oxytricha seokmoensis is most similar to O. pulvillus, but can be distinguished by the number of adoral membranelles (30-40 vs. 23-27), contractile vacuole (present vs; absent), number of left (27-37 vs, 17-25) and right (27-35 vs, 18-23) marginal cirri, and lepidosomes on the cyst surface (present vs. absent). In a phylogenetic tree, O. seokmoensis is distinctly separated from the O. granutifera Glade, but is sister to the Paroxytricha Glade. In addition, O. seokmoensis and P. longigranulosa have the smallest genetic difference (d = 0.015,23 of 1579 nt difference). This close relationship is supported by incomplete dorsal kinety 3 fragmentation and separated macronuclear nodules in resting cysts. (C) 2019 Elsevier GmbH. All rights reserved.

키워드