title: Unusual distribution of mitochondrial large subunit rRNA in the cytosol during conjugation in Tetrahymena thermophila.
abstract: The distribution of mitochondria during conjugation of the ciliated protozoan Tetrahymena thermophila was surveyed using a mitochondrial stain and fluorescence in situ hybridization (FISH). When the mitochondria-specific stain, Mito-Tracker, was used, the majority of mitochondria were detected in the cortex; their distribution was not changed during conjugation. On the other hand, FISH using mitochondrial large subunit (LSU) rRNA as a probe showed an unusual distribution of signals during conjugation. Unexpectedly, the signals were detected throughout the cytoplasm of conjugating cells. These signals were not observed in pre-mating cells and in exconjugants. The cytosolic localization of mitochondrial rRNA was supported by northern blot analysis using post-mitochondrial RNA fraction at the later stages of conjugation. These observations suggest selective mitochondrial breakdown or transport of LSU rRNA into cytosol. The biological significance of the conjugation-specific appearance of the cytosolic mitochondrial rRNA is discussed.
authors.affiliation: Department of Biology, Faculty of Science, Kanazawa University, Kakuma, Kanazawa 920-1192, Japan. tacobys@aichi-med-u.ac.jp
authors.forename: Takashi
authors.initials: T
authors.lastname: Kobayashi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Endoh
mesh_terms: D000818:Animals; D015152:Blotting, Northern; D003227:Conjugation, Genetic; D003600:Cytosol / Q000378:metabolism* / Q000648:ultrastructure; D017404:In Situ Hybridization, Fluorescence; D008928:Mitochondria / Q000378:metabolism* / Q000648:ultrastructure; D012313:RNA / Q000378:metabolism; D000077278:RNA, Mitochondrial; D016053:RNA, Protozoan / Q000378:metabolism*; D012335:RNA, Ribosomal / Q000378:metabolism*; D016808:Tetrahymena thermophila / Q000235:genetics* / Q000502:physiology / Q000648:ultrastructure
chemical_list: D000077278:RNA, Mitochondrial; D016053:RNA, Protozoan; D012335:RNA, Ribosomal; D012313:RNA