title: Telomere recombination preferentially occurs at short telomeres in telomerase-null type II survivors.
abstract: In telomerase negative yeast cells, Rad52-dependent recombination is activated to maintain telomeres. This recombination-mediated telomere elongation usually involves two independent pathways, type I and type II, and leads to generation of type I and type II survivors. It remains elusive whether the recombination-mediated telomere elongation prefers to take place on shorter or longer telomeres. In this study, we exploited the de novo telomere addition system to examine the telomere recombination event in telomerase negative cells. We show that recombination preferentially occurs on shorter rather than longer telomeres in both pre-survivors and established type II survivors. In type II survivors, the short VII-L telomeres could invade either terminal TG1-3 sequence or short tracts of TG1-3 sequence in subtelomeric Y'-X and Y'-Y' junction to initiate recombination. Unexpectedly, short VII-L telomere recombination still takes place in type II survivors lacking either Rad50 or Rad59, which are required for type II survivor generation in senescing telomerase-null cells. Our results support the notion that Rad50 and Rad59 are not essential for the maintenance of type II survivors once established.
authors.affiliation: The State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China.
authors.forename: Xiao-Hong
authors.initials: XH
authors.lastname: Fu
authors.affiliation: The State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China.
authors.forename: Yi-Min
authors.initials: YM
authors.lastname: Duan
authors.affiliation: The State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China.
authors.forename: Yu-Ting
authors.initials: YT
authors.lastname: Liu
authors.affiliation: School of Life Science and Technology, Shanghai Tech University, Shanghai, China.
authors.forename: Chen
authors.initials: C
authors.lastname: Cai
authors.affiliation: The State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China.
authors.forename: Fei-Long
authors.initials: FL
authors.lastname: Meng
authors.affiliation: The State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China.
authors.forename: Jin-Qiu
authors.initials: JQ
authors.lastname: Zhou
mesh_terms: D000375:Aging / Q000502:physiology*; D001483:Base Sequence; D015139:Blotting, Southern; D004268:DNA-Binding Proteins / Q000235:genetics; D055786:Gene Knockout Techniques; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011995:Recombination, Genetic / Q000502:physiology*; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000502:physiology*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics; D017422:Sequence Analysis, DNA; D019098:Telomerase / Q000172:deficiency*; D016615:Telomere / Q000235:genetics*
chemical_list: D004268:DNA-Binding Proteins; C086930:RAD50 protein, S cerevisiae; C400213:RAD59 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D019098:Telomerase