Relationship between blastocoel cell-free DNA and day-5 blastocyst morphology
- 224 Downloads
Cell-free DNA (cfDNA) which is present in the blastocoel cavity of embryos is believed to result from physiological apoptosis during development. This study assessed cfDNA content and caspase-3 protease activity in day-5 IVF blastocysts to determine if there was a correlation with embryo morphology.
Day-5 IVF blastocysts were scored according to the Gardner and Schoolcraft system (modified to generate a numerical value) and cfDNA was collected following laser-induced blastocoel collapsing prior to cryopreservation in 25 μL of media. cfDNA was quantified via fluorospectrometry and apoptotic activity was assessed via a caspase-3 protease assay using a fluorescent peptide substrate. Data were compared by linear regression.
A total of 32 embryos were evaluated. There was a significant (p < 0.01) and positive correlation (cfDNA = 104.753 + (11.281 × score); R2 = 0.200) between embryo score and cfDNA content. A significant (p < 0.05) and positive correlation (cfDNA = 115.9 + (0.05 × caspase-3); R2= 0.128) was observed between caspase-3 activity and cfDNA levels. There was no significant relationship between caspase-3 activity and embryo morphology score.
This study provides further evidence that cfDNA is present in blastocoel fluid, can be quantified, and positively correlates with embryonic morphology. There is also evidence that at least a portion of the cfDNA present is from intracellular contents of embryonic cells that underwent apoptosis. Additional studies are warranted to determine other physiological sources of the cfDNA in blastocyst fluid and to determine the relationship with cfDNA content, embryo morphology, and chromosomal ploidy status plus implantation potential.
KeywordsCell-free DNA Blastocyst Apoptosis Caspase-3 Morphology
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
All procedures performed in this study involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.
- 2.Balaban B, Gardner DK. Morphological assessment of blastocyst stage embryos: types of grading systems and their reported outcomes. In: Gardner D, Sakkas D, Seli E, Wells D, editors. Human Gametes and Preimplantation Embryos: assessment and diagnosis. New York: Springer Science and Media; 2013. p. 31–43.CrossRefGoogle Scholar
- 3.Mandel P, Metais P. Les acides nucleiques du plasma sanguine chez l’homme. C.R. Acad Sci Paris. 1948;142:241–3.Google Scholar
- 8.Tobler KJ, Zhao Y, Ross R, Benner AT, Xu X, Du L, et al. Blastocoel fluid from differentiated blastocysts harbors embryonic genomic material capable of a whole-genome deoxyribonucleic acid amplification and comprehensive chromosome microarray analysis. Fertil Steril. 2015;104(2):418–25.CrossRefPubMedGoogle Scholar
- 12.Rehman KS, Bukulmez O, Langley M, Carr BR, Nackley AC, Doody KM. Late stages of embryo progression are a much better predictor of clinical pregnancy than early cleavage in intracytoplasmic sperm injection and in vitro fertilization cycles with blastocyst-stage transfer. Fertil Steril. 2007;87:1041–52.CrossRefPubMedGoogle Scholar