Frels W I, Chapman V M
J Exp Zool. 1979 Dec;210(3):553-60. doi: 10.1002/jez.1402100319.
The paternally derived allelic form of the X chromosome linked enzyme phosphoglycerate kinase (PGK-1) is expressed in both the fetus and extraembryonic membranes of 9.5 day post coitum XO (XpO) mouse conceptuses. Previous studies on trophectoderm and primitive endoderm derived extraembryonic membranes in XX conceptuses suggest expression of only the maternally derived X chromosome (Xm). Our results suggest that the observed lack of expression of Xp in the trophectoderm and primitive endoderm derivatives of XX embryos is not an intrinsic property of the Xp chromosome.
父源的X染色体连锁酶磷酸甘油酸激酶（PGK-1）的等位基因形式在交配后9.5天的XO（XpO）小鼠胚胎的胎儿和胚外膜中均有表达。先前对XX胚胎中滋养外胚层和原始内胚层来源的胚外膜的研究表明，只有母源的X染色体（Xm）表达。我们的结果表明，在XX胚胎的滋养外胚层和原始内胚层衍生物中观察到的Xp不表达并非Xp染色体的固有特性。
