title: Telomere elongation facilitated by trichostatin a in cloned embryos and pigs by somatic cell nuclear transfer.
abstract: Telomere attrition and genomic instability are associated with organism aging. Concerns still exist regarding telomere length resetting in cloned embryos and ntES cells, and possibilities of premature aging of cloned animals achieved by somatic cell nuclear transfer (SCNT). Trichostatin A (TSA), a histone deacetylase inhibitor, effectively improves the developmental competence of cloned embryos and animals, and recently contributes to successful generation of human ntES cells by SCNT. To test the function of TSA on resetting telomere length, we analyzed telomeres in cloned blastocysts and pigs following treatment of SCNT embryos with TSA. Here, we show that telomeres of cloned pigs generated by standard SCNT methods are not effectively restored, compared with those of donor cells, however TSA significantly increases telomere lengths in cloned pigs. Telomeres elongate in cloned porcine embryos during early cleavage from one-cell to four-cell stages. Notably, TSA facilitates telomere lengthening of cloned embryos mainly at morula-blastocyst stages. Knockdown of pTert by shRNA in donor cells reduces telomerase activity in cloned blastocysts but does not abrogate telomere elongation in the TSA-treated embryos (p > 0.05). However, genes associated with recombination or telomerase-independent mechanism of alternative lengthening of telomeres (ALT) Rad50 and BLM show increased expression in TSA-treated embryos. These data suggest that TSA may promote telomere elongation of cloned porcine embryos by ALT. Together, TSA can elongate telomeres in cloned embryos and piglets, and this could be one of the mechanisms underlying improved development of cloned embryos and animals treated with TSA.
authors: Laboratory of Embryo Biotechnology, College of Life Science, Northeast Agricultural University, Harbin, China, kqr721726@163.com.
authors: Qingran
authors: Q
authors: Kong
authors: Guangzhen
authors: G
authors: Ji
authors: Bingteng
authors: B
authors: Xie
authors: Jingyu
authors: J
authors: Li
authors: Jian
authors: J
authors: Mao
authors: Juan
authors: J
authors: Wang
authors: Shichao
authors: S
authors: Liu
authors: Lin
authors: L
authors: Liu
authors: Zhonghua
authors: Z
authors: Liu
mesh_terms: D000818:Animals; D001755:Blastocyst / Q000187:drug effects / Q000201:enzymology; D019976:Cloning, Organism; D004790:Enzyme Induction / Q000187:drug effects; D056572:Histone Deacetylase Inhibitors / Q000494:pharmacology*; D006877:Hydroxamic Acids / Q000494:pharmacology*; D053652:Nuclear Transfer Techniques; D034421:Sus scrofa; D019098:Telomerase / Q000378:metabolism; D016615:Telomere / Q000235:genetics; D059505:Telomere Homeostasis / Q000187:drug effects*
chemical_list: D056572:Histone Deacetylase Inhibitors; D006877:Hydroxamic Acids; C012589:trichostatin A; D019098:Telomerase