Telomere lengths in human oocytes, cleavage stage embryos and blastocysts
Open Access
- 23 June 2010
- journal article
- research article
- Published by Oxford University Press (OUP) in Molecular Human Reproduction
- Vol. 16 (9), 685-694
- https://doi.org/10.1093/molehr/gaq048
Abstract
Telomeres are repeated sequences that protect the ends of chromosomes and harbour DNA repair proteins. Telomeres shorten during each cell division in the absence of telomerase. When telomere length becomes critically short, cell senescence occurs. Telomere length therefore reflects both cellular ageing and capacity for division. We have measured telomere length in human germinal vesicle (GV) oocytes and preimplantation embryos, by quantitative fluorescence in situ hybridization (Q-FISH), providing baseline data towards our hypothesis that telomere length is a marker of embryo quality. The numbers of fluorescent foci suggest that extensive clustering of telomeres occurs in mature GV stage oocytes, and in preimplantation embryos. When calculating average telomere length by assuming that each signal presents one telomere, the calculated telomere length decreased from the oocyte to the cleavage stages, and increased between the cleavage stages and the blastocyst (11.12 versus 8.43 versus 12.22 kb, respectively, P < 0.001). Other methods of calculation, based upon expected maximum and minimum numbers of telomeres, confirm that telomere length in blastocysts is significantly longer than cleavage stages. Individual blastomeres within an embryo showed substantial variation in calculated average telomere length. This study implies that telomere length changes according to the stage of preimplantation embryo development.Keywords
This publication has 50 references indexed in Scilit:
- Telomere susceptibility to cigarette smoke-induced oxidative damage and chromosomal instability of mouse embryos in vitroFree Radical Biology & Medicine, 2010
- Analysis of meiotic prophase I in live mouse spermatocytesChromosome Research, 2008
- Permanent embryo arrest: molecular and cellular conceptsMolecular Human Reproduction, 2008
- Offspring's Leukocyte Telomere Length, Paternal Age, and Telomere Elongation in SpermPLoS Genetics, 2008
- Telomere lengthening early in developmentNature, 2007
- Critically short telomeres are associated with sperm DNA fragmentationFertility and Sterility, 2005
- X-chromosome inactivation and telomere size in newborns resulting from intracytoplasmic sperm injectionAmerican Journal of Medical Genetics Part A, 2005
- Telomeres and telomerase: their mechanisms of action and the effects of altering their functionsFEBS Letters, 2004
- Nuclear localization of NORs and centromeres in mouse oocytes during folliculogenesisMolecular Reproduction and Development, 2003
- Induction of DNA replication in germinal vesicles and in nuclei formed in maturing mouse oocytes by 6-DMAP treatmentZygote, 1997