Project name: Homo sapiens

Description: 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.Overall design: Affymetrix SNP arrays were processed according to the manufacturer's directions on DNA extracted from 44 embryos of biopsied blastomere at cleavage stage or biopsied trophectoderm at blastocyst stage and 18 polar bodies biopsied from oocytes,Afflymetrix SNP array analysis was successfully completed on 18 polar body samples from oocytes, 24 blastomere and 20 trophectoderm samples from embryos.

Data type: Variation

Sample scope: Multiisolate

Relevance: Medical

Release date: 2011-07-04

Last updated: 2010-12-06