title: Downregulation of histone methyltransferase genes SUV39H1 and SUV39H2 increases telomere length in embryonic stem-like cells and embryonic fibroblasts in pigs.
abstract: Telomere is a nucleoprotein structure at the ends of chromosomes that helps to protect the ends of chromosomes from being fused with other chromosomes. Knockout of histone methyltransferases Suv39h1 and Suv39h2 increases the telomere length in murine cells, whereas downregulation of SUV39H1 and SUV39H2 genes decreases the telomere length in human cells, suggesting that telomere biology is different among mammalian species. However, epigenetic regulation of the telomere has not been studied in mammals other than the human and mouse. In the present study, the effect of knockdown of SUV39H1 and SUV39H2 genes on telomere length was examined in porcine embryonic stem-like cells (pESLCs) and porcine embryonic fibroblasts (PEFs). The telomeres in SUV39H1 and SUV39H2 knockdown (SUV39KD) pESLCs (37.1 ± 0.9 kb) were longer (P<0.05) compared with those of the control (33.0 ± 0.7 kb). Similarly, SUV39KD PEFs had longer telomeres (22.1 ± 0.4 kb; P<0.05) compared with the control (17.8 ± 1.1 kb). Telomerase activities were not different between SUV39KD pESLCs (10.4 ± 1.7) and the control (10.1 ± 1.7) or between SUV39KD PEFs (1.0 ± 0.3) and the control (1.0 ± 0.4), suggesting that telomerase activities did not contribute to the telomere elongation in SUV39KD pESLCs and SUV39KD PEFs. Relative levels of trimethylation of histone H3 lysine 9 and expressions of DNMT1, DNMT3A and DNMT3B were decreased in SUV39KD cells, suggesting that telomere lengthening in SUV39KD pESLCs and SUV39KD PEFs might be not only related to the loss of histone modification marks but also linked to the decrease in DNA methyltransferase in pigs.
authors.affiliation: Department of Animal Breeding and Reproduction, NARO Institute of Livestock and Grassland Science, Ibaraki 305-0901, Japan. adipy36@affrc.go.jp
authors.forename: Thanh Quang
authors.initials: TQ
authors.lastname: Dang-Nguyen
authors.forename: Seiki
authors.initials: S
authors.lastname: Haraguchi
authors.forename: Tadashi
authors.initials: T
authors.lastname: Furusawa
authors.forename: Tamas
authors.initials: T
authors.lastname: Somfai
authors.forename: Masahiro
authors.initials: M
authors.lastname: Kaneda
authors.forename: Shinya
authors.initials: S
authors.lastname: Watanabe
authors.forename: Satoshi
authors.initials: S
authors.lastname: Akagi
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Kikuchi
authors.forename: Atsushi
authors.initials: A
authors.lastname: Tajima
authors.forename: Takashi
authors.initials: T
authors.lastname: Nagai
mesh_terms: D000818:Animals; D002460:Cell Line; D019175:DNA Methylation; D017931:DNA Primers / Q000235:genetics; D053595:Embryonic Stem Cells / Q000166:cytology*; D044127:Epigenesis, Genetic; D005347:Fibroblasts / Q000166:cytology*; D018507:Gene Expression Regulation, Developmental; D055785:Gene Knockdown Techniques; D000076983:Histone Methyltransferases; D011495:Histone-Lysine N-Methyltransferase / Q000235:genetics / Q000378:metabolism*; D006657:Histones / Q000378:metabolism; D034622:RNA Interference; D013552:Swine; D016615:Telomere / Q000648:ultrastructure*
chemical_list: D017931:DNA Primers; D006657:Histones; D000076983:Histone Methyltransferases; D011495:Histone-Lysine N-Methyltransferase