Y Verlinsky1, S Evsikov. 1. Reproductive Genetics Institute, Chicago, Illinois 60657, USA.
Abstract
OBJECTIVE: To develop a reliable and cost-effective technique for karyotyping single human blastomeres for preimplantation diagnosis of chromosomal translocations. DESIGN: Controlled laboratory study. SETTING: Preimplantation genetic diagnosis and IVF program, Reproductive Genetics Institute/IVF Illinois, Chicago, Illinois. PATIENT(S): Patients undergoing IVF and preimplantation genetic diagnosis. INTERVENTION(S): Individual human blastomeres were fused with enucleated or intact mouse zygotes. After blastomere-cytoplast fusion, heterokaryons were fixed at metaphase of the first cleavage division or treated with okadaic acid to induce premature chromosome condensation. MAIN OUTCOME MEASURE(S): Percentage of analyzable metaphase plates and ease and reliability of the procedure. RESULT(S): The effectiveness of the proposed technique with blastomeres from day 3 diploid embryos was 91%. Sixty-three metaphases were obtained from 69 blastomeres; 3 blastomeres had not fused, 1 heterokaryon had no chromatin (an anucleated cytoplasmic bleb was biopsied and fused), and 2 heterokaryons cleaved before they were fixed. CONCLUSION(S): Human blastomere fusion with an intact mouse zygote is an efficient and technically undemanding method for obtaining metaphase chromosome plates from individual human blastomeres for preimplantation testing for chromosomal translocations and aneuploidy.
OBJECTIVE: To develop a reliable and cost-effective technique for karyotyping single human blastomeres for preimplantation diagnosis of chromosomal translocations. DESIGN: Controlled laboratory study. SETTING: Preimplantation genetic diagnosis and IVF program, Reproductive Genetics Institute/IVF Illinois, Chicago, Illinois. PATIENT(S): Patients undergoing IVF and preimplantation genetic diagnosis. INTERVENTION(S): Individual human blastomeres were fused with enucleated or intact mouse zygotes. After blastomere-cytoplast fusion, heterokaryons were fixed at metaphase of the first cleavage division or treated with okadaic acid to induce premature chromosome condensation. MAIN OUTCOME MEASURE(S): Percentage of analyzable metaphase plates and ease and reliability of the procedure. RESULT(S): The effectiveness of the proposed technique with blastomeres from day 3 diploid embryos was 91%. Sixty-three metaphases were obtained from 69 blastomeres; 3 blastomeres had not fused, 1 heterokaryon had no chromatin (an anucleated cytoplasmic bleb was biopsied and fused), and 2 heterokaryons cleaved before they were fixed. CONCLUSION(S): Human blastomere fusion with an intact mouse zygote is an efficient and technically undemanding method for obtaining metaphase chromosome plates from individual human blastomeres for preimplantation testing for chromosomal translocations and aneuploidy.
Authors: Chantal B Bartels; Reeva Makhijani; Prachi Godiwala; Alison Bartolucci; John C Nulsen; Daniel R Grow; Lawrence Engmann; Claudio A Benadiva Journal: F S Rep Date: 2020-09-25