Eckert J, Niemann H
Department of Biotechnology, Institut für Tierzucht und Tierverhalten (FAL) Mariensee, Neustadt, Germany.
Mol Hum Reprod. 1998 Oct;4(10):957-65. doi: 10.1093/molehr/4.10.957.
Leukaemia inhibitory factor (LIF) plays an essential role during cell differentiation and implantation in the mouse exerting its effects via the two dimerizing receptor subunits glycoprotein 130 (gp130) and LIF-receptor beta (LR-beta). This study investigated the mRNA expression of bovine LIF (bLIF), gp130 and LR-beta in pooled or individual bovine oocytes and embryos generated in vitro or in vivo after superovulation. Transcripts of gp130 and LR-beta were detectable in as little material as 1/3 oocyte equivalent and bLIF transcripts in two embryo equivalents employing a simple, rapid and robust one-step reverse transcription-polymerase chain reaction (RT-PCR) protocol using random hexamer priming during reverse transcription and 60 amplification cycles in the PCR. All mRNA fragments were also found in cumulus cells and various bovine tissues. While gp130 and LR-beta mRNA were present in pooled material throughout embryo development in vitro from the immature oocyte to the hatched blastocyst, bLIF-transcripts were absent in immature oocytes, inconsistently expressed from the matured oocyte up to the 16-cell stage as well as in blastocysts dependent on embryo batch. It was not found in morulae, but again present in hatched blastocysts. In contrast, in in-vivo derived embryos no bLIF was found, LR-beta was not detected at the morula to blastocyst transition while gp130 transcripts were observed from the morula to the hatched blastocyst. In individual embryos the mRNA expression pattern was similar for both in-vitro and in-vivo derived embryos as found in pooled material. These results indicate perturbation of the mRNA expression pattern of the specific LIF-LIF-receptor system in embryos generated in vitro that could lead to abnormal differentiation of the cell compartments forming the blastocyst. Cumulus cells, frequently used as supportive factor in co-culture in bovine in-vitro embryo production, are a rich source of the LIF-LIF-receptor system acting in a paracrine and/or autocrine manner. The biological function of the LIF-LIF-receptor system during bovine preimplantation development warrants further investigation.
白血病抑制因子（LIF）在小鼠的细胞分化和着床过程中发挥着重要作用，它通过两个二聚化受体亚基糖蛋白130（gp130）和LIF受体β（LR-β）发挥作用。本研究调查了牛LIF（bLIF）、gp130和LR-β在超排卵后体外或体内产生的牛卵母细胞和胚胎的混合样本或单个样本中的mRNA表达。使用一种简单、快速且可靠的一步逆转录-聚合酶链反应（RT-PCR）方案，在逆转录过程中使用随机六聚体引物，在PCR中进行60个扩增循环，在低至1/3卵母细胞当量的材料中可检测到gp130和LR-β的转录本，在两个胚胎当量的材料中可检测到bLIF转录本。在卵丘细胞和各种牛组织中也发现了所有mRNA片段。虽然在体外从未成熟卵母细胞到孵化囊胚的整个胚胎发育过程中，混合样本中都存在gp130和LR-β mRNA，但未成熟卵母细胞中不存在bLIF转录本，从成熟卵母细胞到16细胞阶段以及囊胚中bLIF转录本的表达不一致，具体取决于胚胎批次。在桑葚胚中未发现bLIF转录本，但在孵化囊胚中再次出现。相比之下，在体内来源的胚胎中未发现bLIF，在桑葚胚到囊胚转变阶段未检测到LR-β，而从桑葚胚到孵化囊胚可观察到gp130转录本。在单个胚胎中，体外和体内来源胚胎的mRNA表达模式与混合样本中相似。这些结果表明，体外产生的胚胎中特定LIF-LIF受体系统的mRNA表达模式受到干扰，这可能导致形成囊胚的细胞区室异常分化。卵丘细胞在牛体外胚胎生产中共培养时经常用作支持因子，是LIF-LIF受体系统的丰富来源，以旁分泌和/或自分泌方式发挥作用。LIF-LIF受体系统在牛植入前发育过程中的生物学功能值得进一步研究。
