Open AccessTelomerase Activity in Early Bovine Embryos Derived from Parthenogenetic Activation and Nuclear Transfer1
Author(s) -
Jie Xu,
Xiangzhong Yang
Publication year - 2001
Publication title -
biology of reproduction
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.366
H-Index - 180
eISSN - 1529-7268
pISSN - 0006-3363
DOI - 10.1095/biolreprod64.3.770
Subject(s) - telomerase , biology , telomere , blastocyst , embryo , somatic cell , zygote , somatic cell nuclear transfer , parthenogenesis , telomerase rna component , genetics , microbiology and biotechnology , dna , telomerase reverse transcriptase , embryogenesis , gene
This study examined the telomerase activity in preimplantation bovine embryos derived from either parthenogenetic activation or nuclear transfer. Telomeres are the DNA-protein structures located at the ends of eukaryotic chromosomes. Telomerase is the ribonuclear enzyme that helps to restore telomere length by synthesizing telomeric DNA repeat (5'-TTAGGG-3') from its own RNA template. Without telomerase activity, telomeres shorten with each cell division through conventional DNA replication. In most mammalian species, telomerase activity is present in germ cells but not in somatic cells. Previously, we reported the dynamics of telomerase activity in bovine in vitro fertilized (IVF) embryos. In the present study, we examined the telomerase activity in bovine embryos derived either from parthenogenetic activation or somatic cell nuclear transfer (i.e., cloning). Embryos from both sources were harvested at different stages, from zygote to blastocyst. Telomerase activity in embryos derived from parthenogenetic activation and nuclear transfer showed a dynamic profile similar to that of those derived from IVF. Telomerase activity was detected in embryos at all stages examined, with the highest level in the blastocyst stage, regardless of the method of embryo production.