Olga Tšuiko1, Daria I Zhigalina2, Tatjana Jatsenko3, Nikolay A Skryabin4, Olga R Kanbekova5, Victoria G Artyukhova6, Anatoly V Svetlakov6, Katre Teearu7, Aleksander Trošin8, Andres Salumets9, Ants Kurg7, Igor N Lebedev10. 1. Department of Biomedicine, Institute of Bio- and Translational Medicine, University of Tartu, Tartu, Estonia; Competence Center on Health Technologies, Tartu, Estonia; Department of Biotechnology, Institute of Molecular and Cell Biology, University of Tartu, Tartu, Estonia. Electronic address: olga.tsuiko@ccht.ee. 2. Laboratory of Molecular Diagnostics, Research Institute of Medical Genetics, Tomsk, National Research Medical Center of Russian Academy of Science, Tomsk, Russian Federation; Department of Cytology and Genetics, National Research Tomsk State University, Tomsk, Russian Federation. 3. Competence Center on Health Technologies, Tartu, Estonia. 4. Laboratory of Molecular Diagnostics, Research Institute of Medical Genetics, Tomsk, National Research Medical Center of Russian Academy of Science, Tomsk, Russian Federation. 5. Department of Assisted Reproductive Technology, Tomsk Regional Perinatal Center, Tomsk, Russian Federation. 6. Department of Embryology, Krasnoyarsk Center for Reproductive Medicine, Krasnoyarsk, Russian Federation. 7. Department of Biotechnology, Institute of Molecular and Cell Biology, University of Tartu, Tartu, Estonia. 8. Women's Clinic, East-Tallinn Central Hospital, Tallinn, Estonia. 9. Department of Biomedicine, Institute of Bio- and Translational Medicine, University of Tartu, Tartu, Estonia; Competence Center on Health Technologies, Tartu, Estonia; Department of Obstetrics and Gynecology, Institute of Clinical Medicine, University of Tartu, Tartu, Estonia; Department of Obstetrics and Gynecology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland. 10. Cytogenetics Laboratory, Research Institute of Medical Genetics, Tomsk National Research Medical Center of Russian Academy of Sciences, Tomsk, Russian Federation; Department of Medical Genetics, Siberian State Medical University, Tomsk, Russian Federation.
Abstract
OBJECTIVE: To compare the genomic profiles of blastocoel fluid (BF), inner cell mass (ICM), and trophectoderm (TE) cells derived from the same blastocyst. DESIGN: Prospective study. SETTING: Academic and in vitro fertilization units. PATIENT(S): Sixteen donated cryopreserved embryos at blastocyst stage. INTERVENTION(S): BF, TE, and ICM cells were retrieved from each blastocyst for chromosome analysis by means of next-generation sequencing (NGS). MAIN OUTCOME MEASURE(S): Aneuploidy screening and assessment of mosaicism in BF, TE and ICM samples with subsequent comparison of genomic profiles between the three blastocyst compartments. RESULT(S): Out of 16 blastocysts, 10 BF samples and 14 TE and ICM samples provided reliable NGS data for comprehensive chromosome analysis. Only 40.0% of BF-DNA karyotypes were fully concordant with TE or ICM, compared with 85.7% concordance between TE and ICM. In addition, BF-DNA was burdened with mosaic aneuploidies and the total number of affected chromosomes in BF was significantly higher compared with the TE and ICM. CONCLUSION(S): BF-DNA can be successfully amplified and subjected to NGS, but owing to increased discordance with ICM and TE, BF does not adequately represent the status of the rest of the embryo. To overcome biologic and technical challenges associated with BF sampling and processing, blastocentesis would require improvement in both laboratory protocols and aneuploidy calling algorithms. Therefore, TE biopsy remains the most effective way to predict embryonic karyotype, and the use of BF as a single source of DNA for preimplantation genetic screening is not yet advised.
OBJECTIVE: To compare the genomic profiles of blastocoel fluid (BF), inner cell mass (ICM), and trophectoderm (TE) cells derived from the same blastocyst. DESIGN: Prospective study. SETTING: Academic and in vitro fertilization units. PATIENT(S): Sixteen donated cryopreserved embryos at blastocyst stage. INTERVENTION(S): BF, TE, and ICM cells were retrieved from each blastocyst for chromosome analysis by means of next-generation sequencing (NGS). MAIN OUTCOME MEASURE(S): Aneuploidy screening and assessment of mosaicism in BF, TE and ICM samples with subsequent comparison of genomic profiles between the three blastocyst compartments. RESULT(S): Out of 16 blastocysts, 10 BF samples and 14 TE and ICM samples provided reliable NGS data for comprehensive chromosome analysis. Only 40.0% of BF-DNA karyotypes were fully concordant with TE or ICM, compared with 85.7% concordance between TE and ICM. In addition, BF-DNA was burdened with mosaic aneuploidies and the total number of affected chromosomes in BF was significantly higher compared with the TE and ICM. CONCLUSION(S): BF-DNA can be successfully amplified and subjected to NGS, but owing to increased discordance with ICM and TE, BF does not adequately represent the status of the rest of the embryo. To overcome biologic and technical challenges associated with BF sampling and processing, blastocentesis would require improvement in both laboratory protocols and aneuploidy calling algorithms. Therefore, TE biopsy remains the most effective way to predict embryonic karyotype, and the use of BF as a single source of DNA for preimplantation genetic screening is not yet advised.
Authors: Laura D Vagnini; Claudia G Petersen; Adriana Renzi; Felipe Dieamant; João B A Oliveira; Antonio H Oliani; Maria C T Canas; Raul Nakano; Carlos G Almodin; Condesmar Marcondes; Alvaro Ceschin; Adelino Amaral; Jonathas B Soares; Joaquim Lopes; Antonio C Franco; Jose G Franco Journal: JBRA Assist Reprod Date: 2020-10-06