Telomere lengths in human oocytes, cleavage stage embryos and blastocysts

Turner, S.; Wong, Hiu-Pak; Rai, J.; Hartshorne, Geraldine M.

doi:10.1093/molehr/gaq048

Cited by 71 publications

(46 citation statements)

References 46 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Limited data is available on telomere shortening in couples experiencing recurrent spontaneous abortion and our results are consistent with the study by Turner et al [45]. To our knowledge, this is the first study addressing the potential contributions of relative telomere length in both partners of couple experiencing in iRPL.…”

Section: Discussionsupporting

confidence: 91%

Analysis of telomere length in couples experiencing idiopathic recurrent pregnancy loss

Thilagavathi

Mishra

Kumar

et al. 2013

J Assist Reprod Genet

View full text Add to dashboard Cite

Purpose Telomere length plays a significant role in various disorders; however, its role in idiopathic recurrent pregnancy loss (iRPL) is not known. The objective of this study was to assess telomere length in peripheral blood leukocytes in couples experiencing unexplained recurrent pregnancy loss (iRPL). Methods The study included 25 couples experiencing iRPL and 20 controls. The mean relative telomere length was measured by quantitative Real Time PCR (Q-PCR) based assay, which measures the average ratio of telomere repeat copy number to a single copy gene (36B4) copy number (T/S ratio) in each sample. Results The relative leukocyte mean telomere length (T/S) in both men and women from iRPL group was significantly lower (p<0.05) when compared to controls. A significant (P<0.05) negative correlation was found between age and leukocyte telomere length (T/S ratio). Among the sperm parameters seminal volume was found to be negatively (r = −0.4679) associated with the telomere T/S ratio. The DNA fragmentation index of sperm showed positive correlation (r=0.4744) with telomere length. In this preliminary study, we found that shorter telomere length in both men and women may be associated with early pregnancy loss. Conclusion In conclusion, shorter telomere length in both male and female partners appears to play a role in the idiopathic recurrent pregnancy loss. Loss of telomeric DNA due to oxidative stress needs further analysis. Analysis of telomere length in germ cells are needed to further substantiate the findings of this study.

show abstract

Section: Discussionsupporting

confidence: 91%

Analysis of telomere length in couples experiencing idiopathic recurrent pregnancy loss

Thilagavathi

Mishra

Kumar

et al. 2013

J Assist Reprod Genet

View full text Add to dashboard Cite

show abstract

“…This phenomenon has been observed in animals [21], [22] and recently by unpaired analysis in humans [23]. Telomere DNA was quantified in the 1 st and 2 nd polar body and a blastomere from each of 21 cleavage stage embryos, and in the 1 st and 2 nd polar body and a trophectoderm biopsy from each of 29 blastocyst stage embryos.…”

Section: Resultsmentioning

confidence: 66%

Telomere DNA Deficiency Is Associated with Development of Human Embryonic Aneuploidy

et al. 2011

View full text Add to dashboard Cite

Aneuploidy represents the most prevalent form of genetic instability found in human embryos and is the leading genetic cause of miscarriage and developmental delay in newborns. Telomere DNA deficiency is associated with genomic instability in somatic cells and may play a role in development of aneuploidy commonly found in female germ cells and human embryos. To test this hypothesis, we developed a method capable of quantifying telomere DNA in parallel with 24-chromosome aneuploidy screening from the same oocyte or embryo biopsy. Aneuploid human polar bodies possessed significantly less telomere DNA than euploid polar bodies from sibling oocytes (−3.07 fold, P = 0.016). This indicates that oocytes with telomere DNA deficiency are prone to aneuploidy development during meiosis. Aneuploid embryonic cells also possessed significantly less telomere DNA than euploid embryonic cells at the cleavage stage (−2.60 fold, P = 0.002) but not at the blastocyst stage (−1.18 fold, P = 0.340). The lack of a significant difference at the blastocyst stage was found to be due to telomere DNA normalization between the cleavage and blastocyst stage of embryogenesis and not due to developmental arrest of embryos with short telomeres. Heterogeneity in telomere length within oocytes may provide an opportunity to improve the treatment of infertility through telomere-based selection of oocytes and embryos with reproductive competence.

show abstract

“…Telomere images were exported as 8-bit tagged image file format (tiff) files and analyzed using the TFL-telo program [36,37]. Fluorescent densities of individual dots were measured to calculate average densities.…”

Section: Methodsmentioning

confidence: 99%

Age-associated telomere shortening in mouse oocytes

Yamada-Fukunaga

Yamada

Hamatani

et al. 2013

Reprod Biol Endocrinol

View full text Add to dashboard Cite

BackgroundOocytes may undergo two types of aging. The first is induced by exposure to an aged ovarian microenvironment before being ovulated, known as ‘reproductive or maternal aging’, and the second by either a prolonged stay in the oviduct before fertilization or in vitro aging prior to insemination, known as ‘postovulatory aging’. However, the molecular mechanisms underlying these aging processes remain to be elucidated. As telomere shortening in cultured somatic cells triggers replicative senescence, telomere shortening in oocytes during reproductive and postovulatory aging may predict developmental competence. This study aimed to ascertain the mechanisms underlying altered telomere biology in mouse oocytes during reproductive and postovulatory aging.MethodsWe studied Tert expression patterns, telomerase activity, cytosolic reactive oxygen species (ROS) production, and telomere length in fresh oocytes from young versus reproductively-aged female mice retrieved from oviducts at 14 h post-human chorionic gonadotropin (hCG), in vivo or in vitro postovulatory-aged mouse oocytes at 23 h post-hCG. Oocytes were collected from super-ovulated C57BL/6 J mice of 6–8 weeks or 42–48 weeks of age. mRNA and protein expressions of the Tert gene were quantified using real-time quantitative reverse transcriptase polymerase chain reaction (Q-PCR) and immunochemistry. Telomerase activity was measured by a telomeric repeat amplification protocol assay, while telomere length was measured by Q-PCR and quantitative fluorescence in situ hybridization analyses.ResultsThe abundance of Tert expression in oocytes significantly decreased during reproductive and postovulatory aging. Immunofluorescent staining clearly demonstrated an altered pattern and intensity of TERT protein expression in oocytes during reproductive aging. Furthermore, relative telomerase activity (RTA) in oocytes from reproductively-aged females was significantly lower than that in oocytes from young females. In contrast, RTA in postovulatory-aged oocytes was similar to that in fresh oocytes. Oocytes from reproductively-aged females and postovulatory-aged oocytes showed higher ROS levels than oocytes from young females. Relative telomere length (RTL) was remarkably shorter in oocytes from reproductively-aged females compared to oocytes from young females. However, postovulatory aging had no significant effect on RTL of oocytes.ConclusionsLong-term adverse effects of low telomerase activity and increased ROS exposure are likely associated with telomere shortening in oocytes from reproductively-aged female mice.

show abstract

Telomere lengths in human oocytes, cleavage stage embryos and blastocysts

Cited by 71 publications

References 46 publications

Analysis of telomere length in couples experiencing idiopathic recurrent pregnancy loss

Analysis of telomere length in couples experiencing idiopathic recurrent pregnancy loss

Telomere DNA Deficiency Is Associated with Development of Human Embryonic Aneuploidy

Age-associated telomere shortening in mouse oocytes

Contact Info

Product

Resources

About