title: Female sex bias in human embryonic stem cell lines.
abstract: The factors limiting the rather inefficient derivation of human embryonic stem cells (HESCs) are not fully understood. The aim of this study was to analyze the sex ratio in our 42 preimplantation genetic diagnosis (PGD)-HESC lines, in an attempt to verify its affect on the establishment of HESC lines. The ratio between male and female PGD-derived cell lines was compared. We found a significant increase in female cell lines (76%). This finding was further confirmed by a meta-analysis for combining the results of all PGD-derived HESC lines published to date (148) and all normal karyotyped HESC lines derived from spare in vitro fertilization embryos worldwide (397). Further, gender determination of embryos demonstrated that this difference originates from the actual derivation process rather than from unequal representation of male and female embryos. It can therefore be concluded that the clear-cut tendency for female preponderance is attributed to suboptimal culture conditions rather than from a true gender imbalance in embryos used for derivation of HESC lines. We propose a mechanism in which aberrant X chromosome inactivation and/or overexpression of critical metabolic X-linked genes might explain this sex dimorphism.
authors.affiliation: Department of Cell and Developmental Biology Sackler Medical School, Tel Aviv Sourasky Medical Center, Tel Aviv University, Lis Maternity Hospital, Tel Aviv, Israel.
authors.forename: Dalit
authors.initials: D
authors.lastname: Ben-Yosef
authors.forename: Ami
authors.initials: A
authors.lastname: Amit
authors.forename: Mira
authors.initials: M
authors.lastname: Malcov
authors.forename: Tsvia
authors.initials: T
authors.lastname: Frumkin
authors.forename: Ahmi
authors.initials: A
authors.lastname: Ben-Yehudah
authors.forename: Ido
authors.initials: I
authors.lastname: Eldar
authors.forename: Nava
authors.initials: N
authors.lastname: Mey-Raz
authors.forename: Foad
authors.initials: F
authors.lastname: Azem
authors.forename: Gheona
authors.initials: G
authors.lastname: Altarescu
authors.forename: Paul
authors.initials: P
authors.lastname: Renbaum
authors.forename: Rachel
authors.initials: R
authors.lastname: Beeri
authors.forename: Irit
authors.initials: I
authors.lastname: Varshaver
authors.forename: Talia
authors.initials: T
authors.lastname: Eldar-Geva
authors.forename: Silvina
authors.initials: S
authors.lastname: Epsztejn-Litman
authors.forename: Ephrat
authors.initials: E
authors.lastname: Levy-Lahad
authors.forename: Rachel
authors.initials: R
authors.lastname: Eiges
mesh_terms: D015415:Biomarkers / Q000032:analysis; D002460:Cell Line; D002877:Chromosomes, Human / Q000502:physiology; D004622:Embryo, Mammalian / Q000166:cytology / Q000502:physiology*; D047108:Embryonic Development; D053595:Embryonic Stem Cells / Q000166:cytology* / Q000502:physiology; D005260:Female; D015894:Genome, Human; D006801:Humans; D059785:Karyotype; D008297:Male; D019836:Preimplantation Diagnosis; D012744:Sex Ratio; D049951:X Chromosome Inactivation
chemical_list: D015415:Biomarkers