Stewart C L, Kaspar P, Brunet L J, Bhatt H, Gadi I, Köntgen F, Abbondanzo S J
Department of Cell and Developmental Biology, Roche Institute of Molecular Biology, Nutley, New Jersey 07110.
Nature. 1992 Sep 3;359(6390):76-9. doi: 10.1038/359076a0.
A critical point during mammalian pregnancy is the implantation of the blastocyst when the embryo attaches to the wall of the uterus. The autonomously developing preimplantation embryo then becomes dependent on the maternal environment for its continued development. Little is known about the regulation of implantation, except that a complex interaction between peptide and steroid hormones synchronizes the preparation of the uterus for implantation with the development of the embryo. Whether the implantation event is under maternal or embryonic control is also unclear (reviewed in refs 1, 2). We have previously shown that a cytokine, leukaemia inhibitory factor (LIF), is expressed in the uterine endometrial glands specifically on the fourth day of pregnancy. This burst of expression is under maternal control and always precedes implantation of the blastocyst. Here we report that transient expression of LIF in mice is essential for implantation. Females lacking a functional LIF gene are fertile, but their blastocysts fail to implant and do not develop. The blastocysts, however, are viable and, when transferred to wild-type pseudopregnant recipients, they can implant and develop to term.
哺乳动物怀孕过程中的一个关键点是囊胚着床，即胚胎附着于子宫壁之时。自主发育的着床前胚胎随后开始依赖母体环境以继续发育。除了肽类激素和甾体激素之间的复杂相互作用使子宫为着床所做的准备与胚胎发育同步外，关于着床的调控所知甚少。着床事件是受母体控制还是胚胎控制也尚不清楚（参考文献1、2中有综述）。我们之前已表明，一种细胞因子，即白血病抑制因子（LIF），在怀孕第4天特异性地在子宫内膜腺体中表达。这种表达的突然增加受母体控制，并且总是先于囊胚着床。在此我们报告，LIF在小鼠中的瞬时表达对着床至关重要。缺乏功能性LIF基因的雌性具有生育能力，但其囊胚无法着床且不能发育。然而，这些囊胚是有活力的，当移植到野生型假孕受体中时，它们能够着床并发育至足月。
