title: Conservation and characterization of unique porcine interstitial telomeric sequences.
abstract: Telomeres are composed of TTAGGG repeats and located at the ends of chromosomes. Telomeres protect chromosomes from instability in mammals, including mice and humans. Repetitive TTAGGG sequences are also found at intrachromosomal sites, where they are named as interstitial telomeric sequences (ITSs). Aberrant ITSs are implicated in chromosomal instability and found in cancer cells. Interestingly, in pigs, vertebrate telomere sequences TTAGGG (vITSs) are also localized at the centromeric region of chromosome 6, in addition to the end of all chromosomes. Surprisingly, we found that botanic telomere sequences, TTTAGGG (bITSs), also localize with vITSs at the centromeric regions of pig chromosome 6 using telomere fluorescence in situ hybridization (FISH) and by comparisons between several species. Furthermore, the average lengths of vITSs are highly correlated with those of the terminal telomeres (TTS). Also, pig ITSs show a high incidence of telomere doublets, suggesting that pig ITSs might be unstable and dynamic. Together, our results show that pig cells maintain the conserved telomere sequences that are found at the ITSs from of plants and other vertebrates. Further understanding of the function and regulation of pig ITSs may provide new clues for evolution and chromosomal instability.
authors.affiliation: State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai University, Tianjin 300071, China.
authors.forename: Guangzhen
authors.initials: G
authors.lastname: Ji
authors.forename: Kai
authors.initials: K
authors.lastname: Liu
authors.forename: Chengbin
authors.initials: C
authors.lastname: Chen
authors.forename: Weimin
authors.initials: W
authors.lastname: Ruan
authors.forename: Christina
authors.initials: C
authors.lastname: Glytsou
authors.forename: Yang
authors.initials: Y
authors.lastname: Yang
authors.forename: Maja
authors.initials: M
authors.lastname: Okuka
authors.forename: Wenqing
authors.initials: W
authors.lastname: Song
authors.forename: Sarantis
authors.initials: S
authors.lastname: Gagos
authors.forename: Ning
authors.initials: N
authors.lastname: Li
authors.forename: Lin
authors.initials: L
authors.lastname: Liu
mesh_terms: D000818:Animals; D017404:In Situ Hybridization, Fluorescence; D012854:Sister Chromatid Exchange; D013552:Swine / Q000235:genetics*; D016615:Telomere