[Original Article]Parental Origin of chromosome sets in human embryos derived from tri-pronuclear zygotes

[ABSTRACT]【Objective】Tripronuclear (3PN) zygotes derived from conventional in vitro fertilization (c-IVF) exhibit diandric triploidy due to dispermic fertilization. These zygotes may spontaneously convert to diploid and develop into morphologically normal blastocysts, potentially making them candidates for embryo transfer. However, limited evidence confirms that these diploid blastocysts have biparental inheritance. This study aimed to determine the parental origin of chromosomes in 3PN zygotes and assess their potential conversion to biparental diploidy. 【Methods】Tripronuclear zygotes observed in c-IVF culture were analyzed. After the first mitotic division, day 2 embryos were dissociated into single blastomeres (2–5 cells per embryo), lysed, and subjected to whole-genome amplification using Phi 29 DNA polymerase, followed by short tandem repeat polymorphism analysis. Ploidy determination was performed via 25–72 PCR reactions per zygote, using an aliquot of the diluted lysate as the PCR template. 【Results】A total of 509 PCR reactions were conducted for 11 3PN zygotes, yielding 84 amplicons in 82 reactions: a single amplicon in 80 (15.7%) reactions and two amplicons in four (0.4%) reactions. The remaining 427 (83.9%) reactions produced no amplicons. The parental origin of chromosomes was estimated as follows: biparental diploid origin (one paternal and one maternal allele each) in 4 zygotes (36%), diandric triploid origin (two paternal alleles and one maternal allele) in 6 zygotes (55%), and androgenetic origin (two paternal alleles and no maternal allele) in 1 zygote (9%). 【Conclusions】These findings suggest that c-IVF-derived 3PN embryos (triploid) may convert to biparental diploid during the first mitotic division. However, further studies using comprehensive and complementary methods are needed to confirm their suitability for embryo transfer.

https://opac.ll.chiba-u.jp/da/curator/900123466/

The Chiba Medical Society

千葉医学会

Journal Article

AN00142148

Chiba medical journal

101E

3

39

48

2025-09-10

10.20776/S03035476-101E-3-P39

publisher

Chiba Medical Journal (ONLINE ISSN 2433-4235)