Nuclear progestin receptor (pgr) knockouts in zebrafish demonstrate role for pgr in ovulation but not in rapid non-genomic steroid mediated meiosis resumption.
Nuclear progestin receptor (pgr) knockouts in zebrafish demonstrate role for pgr in ovulation but not in rapid non-genomic steroid mediated meiosis resumption.
复制标题
斑马鱼核孕激素受体 (pgr) 敲除证明了 pgr 在排卵中的作用，但在快速非基因组类固醇介导的减数分裂恢复中没有作用。
DOI：
10.3389/fendo.2015.00037
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发表时间：
2015
影响因子：
5.2
通讯作者：
Stellwag EJ
中科院分区：
文献类型：
--
作者：
Zhu Y;Liu D;Shaner ZC;Chen S;Hong W;Stellwag EJ
孕激素是一种孕酮衍生物，是启动最终卵母细胞成熟和排卵的最关键的信号类固醇，以促进完全发育的未成熟卵母细胞成为基础脊椎动物中的受精卵。已充分确定的是，孕酮至少部分地通过膜受体和非基因组类固醇信号传导过程诱导FOM，其先于孕酮触发的排卵，所述排卵通过核孕酮受体（Pgr）和基因组信号传导途径介导。为了确定Pgr是否在FOM期间的非基因组信号传导机制中起作用，我们使用转录激活因子样效应核酸酶（TALEN）敲除斑马鱼中的Pgr，并研究Pgr敲除（Pgr-KO）的卵母细胞成熟表型。产生了具有不同移码突变的三个TALEN诱导的突变株系。纯合Pgr-KO雌性鱼都是不育的，而在纯合Pgr-KO雄性鱼中没有明显的生育力影响。与野生型对照相比，在纯合Pgr-KO雌性中，卵母细胞在体内正常发育并经历FOM，但这些成熟卵母细胞被困在卵泡细胞内，无法从卵巢排卵。这些卵母细胞在体外也经历了正常的生殖囊泡破裂（GVBD）和FOM，但即使用人慢性促性腺激素（HCG）或孕酮（17α，20 β-二羟孕酮或DHP）处理后也未能排卵，这通常会诱导野生型卵母细胞的FOM和排卵。结果表明，在纯合子Pgr-KO雌性鱼的无排卵和不孕症，至少部分是由于缺乏功能性Pgr介导的基因组的卵母细胞附近的卵泡细胞中的resistin信号。我们对Pgr-KO的研究支持了先前的结果，这些结果证明了Pgr在导致排卵的类固醇依赖性基因组信号传导途径中的作用，并且第一个令人信服的证据表明，Pgr对于启动非基因组孕酮信号传导和触发减数分裂恢复并不重要。
Progestins, progesterone derivatives, are the most critical signaling steroid for initiating final oocyte maturation (FOM) and ovulation, in order to advance fully-grown immature oocytes to become fertilizable eggs in basal vertebrates. It is well-established that progestin induces FOM at least partly through a membrane receptor and a non-genomic steroid signaling process, which precedes progestin triggered ovulation that is mediated through a nuclear progestin receptor (Pgr) and genomic signaling pathway. To determine whether Pgr plays a role in a non-genomic signaling mechanism during FOM, we knocked out Pgr in zebrafish using transcription activator-like effector nucleases (TALENs) and studied the oocyte maturation phenotypes of Pgr knockouts (Pgr-KOs). Three TALENs-induced mutant lines with different frame shift mutations were generated. Homozygous Pgr-KO female fish were all infertile while no fertility effects were evident in homozygous Pgr-KO males. Oocytes developed and underwent FOM normally in vivo in homozygous Pgr-KO female compared to the wild-type controls, but these mature oocytes were trapped within the follicular cells and failed to ovulate from the ovaries. These oocytes also underwent normal germinal vesicle breakdown (GVBD) and FOM in vitro, but failed to ovulate even after treatment with human chronic gonadotropin (HCG) or progestin (17α,20β-dihydroxyprogesterone or DHP), which typically induce FOM and ovulation in wild-type oocytes. The results indicate that anovulation and infertility in homozygous Pgr-KO female fish was, at least in part, due to a lack of functional Pgr-mediated genomic progestin signaling in the follicular cells adjacent to the oocytes. Our study of Pgr-KO supports previous results that demonstrate a role for Pgr in steroid-dependent genomic signaling pathways leading to ovulation, and the first convincing evidence that Pgr is not essential for initiating non-genomic progestin signaling and triggering of meiosis resumption.