Sexing of preimplantation mouse embryos by measurement of X-linked gene dosage in a single blastomere.
Single blastomeres were isolated from zona-free 8-cell mouse embryos and assayed for X-linked hypoxanthine phosphoribosyl transferase (HPRT) activity and autosome-linked adenine phosphoribosyl transferase (APRT) activity. At this stage of development both X chromosomes are active in female embryos. Hence, a bimodal distribution of HPRT: APRT ratios, corresponding to male (XY) and female (XX) biopsied samples, was observed due to the 2-fold difference in gene dosage for HPRT activity. Batches of putative male and female embryos identified in this way were transferred to pseudopregnant recipient females. Development of the seven-eighths embryos was equivalent to that of control zona-free intact embryos. Sex determination by measurement of X-linked gene dosage was accurate and rapid enough to allow transfer of embryos of known sex without the need for cryopreservation.
Monk
M
M
MRC Mammalian Development Unit, London, U.K.
Handyside
A H
AH
D000228:Adenine Phosphoribosyltransferase / Q000378:metabolism; D000818:Animals; D001757:Blastomeres / Q000201:enzymology / Q000502:physiology*; D002970:Cleavage Stage, Ovum / Q000502:physiology*; D004624:Embryo Transfer; D008040:Genetic Linkage; D007041:Hypoxanthine Phosphoribosyltransferase / Q000378:metabolism; D051379:Mice; D008815:Mice, Inbred Strains; D009028:Morula / Q000502:physiology*; D012732:Sex Determination Analysis; D014960:X Chromosome / Q000502:physiology*
D000228:Adenine Phosphoribosyltransferase; D007041:Hypoxanthine Phosphoribosyltransferase