title: Cdk3, a conjugation-specific cyclin-dependent kinase, is essential for the initiation of meiosis in Tetrahymena thermophila.
abstract: Meiosis is an important process in sexual reproduction. Meiosis initiation has been found to be highly diverse among species. In yeast, it has been established that cyclin-dependent kinases (Cdks) and cyclins are essential components in the meiosis initiation pathway. In this study, we identified 4 Cdks in the model ciliate, Tetrahymena thermophila, and we found one of them, Cdk3, which is specifically expressed during early conjugation, to be essential for meiosis initiation. Cdk3 deletion led to arrest at the pair formation stage of conjugation. We then confirmed that Cdk3 acts upstream of double-strand break (DSB) formation. Moreover, we detected that Cdk3 is necessary for the expression of many genes involved in early meiotic events. Through proteomic quantification of phosphorylation, co-expression analysis and RNA-Seq analyses, we identified a conjugation-specific cyclin, Cyc2, which most likely partners with Cdk3 to initiate meiosis.
authors.affiliation: a Key Laboratory of Aquatic Biodiversity and Conservation, Institute of Hydrobiology, Chinese Academy of Sciences , Wuhan , People's Republic of China.|b University of Chinese Academy of Sciences , Beijing , People's Republic of China.
authors.forename: Guan-Xiong
authors.initials: GX
authors.lastname: Yan
authors.affiliation: a Key Laboratory of Aquatic Biodiversity and Conservation, Institute of Hydrobiology, Chinese Academy of Sciences , Wuhan , People's Republic of China.|b University of Chinese Academy of Sciences , Beijing , People's Republic of China.
authors.forename: Jing
authors.initials: J
authors.lastname: Zhang
authors.affiliation: c Department of Chromosome Biology and Max F. Perutz Laboratories , Center for Molecular Biology, University of Vienna , Vienna , Austria.
authors.forename: Anura
authors.initials: A
authors.lastname: Shodhan
authors.affiliation: a Key Laboratory of Aquatic Biodiversity and Conservation, Institute of Hydrobiology, Chinese Academy of Sciences , Wuhan , People's Republic of China.|c Department of Chromosome Biology and Max F. Perutz Laboratories , Center for Molecular Biology, University of Vienna , Vienna , Austria.
authors.forename: Miao
authors.initials: M
authors.lastname: Tian
authors.affiliation: a Key Laboratory of Aquatic Biodiversity and Conservation, Institute of Hydrobiology, Chinese Academy of Sciences , Wuhan , People's Republic of China.
authors.forename: Wei
authors.initials: W
authors.lastname: Miao
mesh_terms: D000595:Amino Acid Sequence; D059447:Cell Cycle Checkpoints; D018844:Cyclin-Dependent Kinases / Q000737:chemistry / Q000378:metabolism*; D053903:DNA Breaks, Double-Stranded; D004260:DNA Repair; D008540:Meiosis; D009154:Mutation / Q000235:genetics; D015800:Protozoan Proteins / Q000737:chemistry / Q000378:metabolism*; D016808:Tetrahymena thermophila / Q000166:cytology* / Q000201:enzymology*
chemical_list: D015800:Protozoan Proteins; D018844:Cyclin-Dependent Kinases
keywords: Tetrahymena thermophila; conjugation; cyclin-dependent kinase; meiosis initiation; sexual reproduction