Laboratory of Animal Biotechnology, Agriculture Faculty, University of Buenos Aires (UBA), Argentina.
Reprod Biol Endocrinol. 2011 Feb 1;9:18. doi: 10.1186/1477-7827-9-18.
BMP4 is a member of the transforming growth factor beta (TGFbeta) superfamily and Noggin is a potent BMP inhibitor that exerts its function by binding to BMPs preventing interactions with its receptors. The aim of this work was to investigate the role of BMP4 and Noggin, on oocytes in vitro maturation (m experiments) and embryos in vitro development (c experiments) of bovine.
For m experiments, COCs were collected from slaughterhouse ovaries and in vitro matured in TCM with 100 ng/ml of either BMP4 or Noggin. After 24 h, the nuclear stage of the oocytes was determined by staining with Hoechst 33342. In addition, RT-qPCR was performed on MII oocytes to study the relative concentration of ZAR1, GDF9, BAX, MATER and HSP70 transcripts. Treated oocytes were submitted to parthenogenic activation (PA) or in vitro fertilization (IVF) and cultured in CR2. For c experiments, non-treated matured oocytes were submitted to PA or IVF to generate embryos that were exposed to 100 ng/ml of BMP4 or Noggin in CR2 until day nine of culture. Cleavage, blastocyst and hatching rates, expression pattern of the transcription factor Oct-4 in blastocysts and embryo cell number at day two and nine post-activation or fertilization were evaluated.
We found that Noggin, as BMP4, did not affect oocyte nuclear maturation. Noggin supplementation up-regulated the expression of HSP70 and MATER genes in matured oocytes. Moreover, BMP4 during maturation increased the proportion of Oct-4 positive cells in parthenogenic embryos. On the other hand, when Noggin was added to embryo culture medium, developmental rates of parthenogenic and in vitro fertilized embryos were reduced. However, BMP4 addition decreases the development only for in vitro fertilized embryos. BMP4 and Noggin during culture reduced the proportion of Oct-4-expressing cells.
Our results show that BMP4 is implicated in bovine oocytes maturation and embryo development. Moreover, our findings demonstrate, for the first time, that a correct balance of BMP signaling is needed for proper pre-implantation development of bovine embryos.
BMP4 是转化生长因子-β（TGFβ）超家族的一员， Noggin 是一种有效的 BMP 抑制剂，通过与 BMPs 结合来阻止其与受体的相互作用来发挥作用。本研究的目的是探讨 BMP4 和 Noggin 对牛卵母细胞体外成熟（m 实验）和胚胎体外发育（c 实验）的作用。
在 m 实验中，从屠宰场卵巢中收集 COCs，并在含有 100ng/ml BMP4 或 Noggin 的 TCM 中进行体外成熟。24 小时后，通过 Hoechst 33342 染色确定卵母细胞的核期。此外，还对 MII 卵母细胞进行了 RT-qPCR，以研究 ZAR1、GDF9、BAX、MATER 和 HSP70 转录本的相对浓度。处理后的卵母细胞进行孤雌激活（PA）或体外受精（IVF），并在 CR2 中培养。在 c 实验中，未经处理的成熟卵母细胞进行 PA 或 IVF，以生成胚胎，然后将胚胎暴露于 CR2 中的 100ng/ml BMP4 或 Noggin 中，直至培养第 9 天。评估卵裂、囊胚和孵化率、囊胚中转录因子 Oct-4 的表达模式以及 PA 或 IVF 后第 2 天和第 9 天的胚胎细胞数量。
我们发现 Noggin 与 BMP4 一样，不影响卵母细胞核成熟。Noggin 补充剂上调了成熟卵母细胞中 HSP70 和 MATER 基因的表达。此外，BMP4 在成熟过程中增加了孤雌胚胎中 Oct-4 阳性细胞的比例。另一方面，当 Noggin 添加到胚胎培养液中时，孤雌和体外受精胚胎的发育率降低。然而，BMP4 的添加仅降低了体外受精胚胎的发育。BMP4 和 Noggin 在培养过程中降低了表达 Oct-4 的细胞比例。
我们的结果表明，BMP4 参与了牛卵母细胞的成熟和胚胎发育。此外，我们的研究结果首次表明，正确的 BMP 信号平衡对于牛胚胎的适当植入前发育是必要的。
