title: Discordant Growth of Monozygotic Twins Starts at the Blastocyst Stage: A Case Study.
abstract: Discordant growth is a common complication of monochorionic/diamniotic pregnancies; in approximately 50% of cases, the cause is unknown. The case presented here suggests that discordant growth of monozygotic twins could start during preimplantation development. Two inner cell masses (ICMs) within the same blastocyst may originate in uneven splitting of a single "parental" ICM, or the two ICMs may be formed independently de novo. We studied the transcriptomes of two morphologically distinct ICMs within a single blastocyst using high-resolution RNA sequencing. The data indicated that the two ICM were at different stages of development; one was in the earliest stages of lineage commitment, while the other had already differentiated into epiblast and primitive endoderm. IGF1-mediated signaling is likely to play a key role in ICM growth and to be the major driver behind these differences.
authors.affiliation: Division of Women's Health, Faculty of Life Sciences and Medicine, King's College London and Assisted Conception Unit, Guy's Hospital, London SE1 9RT, UK.
authors.forename: Laila
authors.initials: L
authors.lastname: Noli
authors.affiliation: GENERA: Centre for Reproductive Medicine, Clinica Valle Giulia, 00197 Rome, Italy; GENETYX: Molecular Genetics Laboratory, Via Fermi 1, 36063 Marostica, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Capalbo
authors.affiliation: Genetics Laboratories, Guy's Hospital, SE1 9RT London, UK.
authors.forename: Caroline
authors.initials: C
authors.lastname: Ogilvie
authors.affiliation: Division of Women's Health, Faculty of Life Sciences and Medicine, King's College London and Assisted Conception Unit, Guy's Hospital, London SE1 9RT, UK.
authors.forename: Yacoub
authors.initials: Y
authors.lastname: Khalaf
authors.affiliation: Division of Women's Health, Faculty of Life Sciences and Medicine, King's College London and Assisted Conception Unit, Guy's Hospital, London SE1 9RT, UK. Electronic address: dusko.ilic@kcl.ac.uk.
authors.forename: Dusko
authors.initials: D
authors.lastname: Ilic
mesh_terms: D001755:Blastocyst / Q000166:cytology* / Q000378:metabolism; D046149:Embryo Culture Techniques; D018507:Gene Expression Regulation, Developmental; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D015398:Signal Transduction; D059467:Transcriptome; D014430:Twins, Monozygotic / Q000235:genetics*
chemical_list: C583557:IGF1 protein, human; D007334:Insulin-Like Growth Factor I