Embryonic estrogen receptors: do they have a physiological function?
Embryonic estrogen receptors: do they have a physiological function?
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胚胎雌激素受体：它们具有生理功能吗？
DOI：
10.1289/ehp.95103s769
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发表时间：
1995-10
影响因子：
10.4
通讯作者：
中科院分区：
文献类型：
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作者：
在正常的雌激素靶组织中，雌激素作用是通过特定的核转录因子雌激素受体（ER）介导的。因此，发育中的生物体中雌激素作用的位点由含有ER和其他必需的组织和基因特异性成分的细胞决定，这些成分用于雌激素介导的转录。用免疫细胞化学方法研究雌激素受体在小鼠胚胎生殖道的细胞定位和组织分布。在胎龄13 - 15天的生殖道中观察到ER的核染色。ER在这些早期发育阶段存在于雄性和雌性生殖道的前体中，这可能归因于它们相似的胚胎起源。然而，随着组织在胎儿后期和新生儿早期经历性分化，与男性相比，女性生殖道中的ER增加。在胚胎第10天（性分化前），用免疫印迹法检测小鼠全胚胎提取物中的ER。为了确定ER和孕酮受体基因是否在发育早期表达，我们用逆转录-聚合酶链反应技术检测了植入前小鼠胚胎的RNA。ER mRNA在卵母细胞和受精卵中均有表达。在2-细胞期，信息浓度下降，在5- 8-细胞期达到最低水平。ER mRNA在桑椹胚期检测不到，但在囊胚期又出现。孕激素受体mRNA直到囊胚期才检测到。雌激素受体和孕激素受体基因在胚泡中的胚胎表达表明，在植入前胚胎中可能需要雌激素和孕激素受体。
In normal estrogen target tissues, estrogen action is mediated through a specific nuclear transcription factor, the estrogen receptor (ER). The site of estrogen action in the developing organism is therefore determined by cells that contain ER and other necessary tissue and gene-specific components for estrogen-mediated transcription. Immunocytochemical methods were used to determine the cellular localization and tissue distribution of ERs in reproductive tracts of mouse fetuses. Nuclear staining for ER was observed in reproductive tracts at fetal days 13 to 15. ERs were present in the precursors of both male and female reproductive tracts at these early developmental stages, which may be attributable to their similar embryonic origins. However, as the tissues undergo sexual differentiation at later fetal and early neonatal ages, ER increases in the female reproductive tracts as compared with the male. ER was detected by immunoblotting on fetal day 10 (before sexual differentiation) in extracts of whole mouse embryos. To determine whether ER and progesterone receptor genes are expressed earlier in development, we examined RNA from preimplantation mouse embryos using reverse transcriptase-polymerase chain reaction techniques. ER mRNA was found in oocytes and fertilized eggs. Message concentration declined at the 2-cell stage and reached its lowest level at the 5- to 8-cell stage. ER mRNA was not detectable at the morula stage but reappeared at the blastocyst stage. Progesterone receptor mRNA was not detectable until the blastocyst stage. The embryonic expression of ER and progesterone receptor genes in the blastocyst suggests a possible functional requirement for estrogen and progesterone receptors in preimplantation embryos.