title: Fluorescence in situ hybridization with specific oligonucleotide rRNA probes distinguishes the sibling species Stylonychia lemnae and Stylonychia mytilus (Ciliophora, Spirotrichea).
abstract: Based on morphological and morphogenetic characters alone, the sibling species Stylonychia lemnae and Stylonychia mytilus, members of the Stylonychia mytilus complex, can hardly be distinguished. However, biochemical investigations of the isoenzyme pattern of different enzymes showed a distinct differentiation between these two species. In the last few years, fluorescence in situ hybridization (FISH) techniques have become a suitable and reliable tool for identification and differentiation of closely related species of protozoa, such as ciliates. To distinguish the sibling species, a set of specific oligonucleotide probes were developed. In the present study, the SSU rDNA of 7 clones of Stylonychia lemnae and 13 clones of Stylonychia mytilus, isolated from different geographic regions, were sequenced. Comparing all SSU rDNA sequences of both species, only one single difference within the whole gene was detected. Based on this difference, a set of two oligonucleotide probes, targeting the SSU rRNA of each species (Stylonychia mytilus and Stylonychia lemnae) was designed. These probes were successfully tested by applying the FISH techniques on preserved cells of different clones of both species.
authors.affiliation: Institute of Biology II, Department of Molecular Evolution and Animal Systematics, University of Leipzig, Talstrasse 33, 04103 Leipzig, Germany. sschmidt@rz.uni-leipzig.de
authors.forename: Stephanie L
authors.initials: SL
authors.lastname: Schmidt
authors.forename: Detlef
authors.initials: D
authors.lastname: Bernhard
authors.forename: Martin
authors.initials: M
authors.lastname: Schlegel
authors.forename: Johannes
authors.initials: J
authors.lastname: Fried
mesh_terms: D000818:Animals; D001483:Base Sequence; D016798:Ciliophora / Q000145:classification* / Q000235:genetics; D016054:DNA, Protozoan / Q000032:analysis; D017404:In Situ Hybridization, Fluorescence / Q000379:methods*; D008969:Molecular Sequence Data; D015345:Oligonucleotide Probes; D012335:RNA, Ribosomal / Q000235:genetics*; D017422:Sequence Analysis, DNA; D013045:Species Specificity
chemical_list: D016054:DNA, Protozoan; D015345:Oligonucleotide Probes; D012335:RNA, Ribosomal