Albrecht Eugene D, Billiar Reinhart B, Aberdeen Graham W, Babischkin Jeffery S, Pepe Gerald J
Departments of Obstetrics, Gynecology, Reproductive Sciences, and Physiology, Center for Studies in Reproduction, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA.
Biol Reprod. 2004 Apr;70(4):1106-13. doi: 10.1095/biolreprod.103.022665. Epub 2003 Dec 10.
Although studies in transgenic mice suggest that estrogen is important for development of the testis, very little is known about the potential role of estrogen in maturation of the primate fetal testis. Therefore, as a first step to determine whether estrogen regulates maturation of the fetal primate testis, we used immunocytochemistry to determine estrogen receptor (ER) alpha and beta expression in the fetal baboon testis. Second, we established methods to quantify ERbeta mRNA levels by competitive reverse transcription-polymerase chain reaction in Sertoli cells isolated by laser capture microdissection (LCM) from the fetal baboon testis. ERbeta protein expression was abundant in the nuclei of Sertoli, peritubular, and interstitial cells in baboon fetuses at mid (Day 100) and late (Day 165) gestation (term is 184 days). ERbeta mRNA level was 0.03 attomole/femtomole 18S rRNA in Sertoli cell nuclei and associated cytoplasm isolated by LCM. ERalpha was expressed in low level in seminiferous tubules and in moderate level in peritubular cells on Day 165. Germ cells expressed very little ERalpha or ERbeta protein, whereas the baboon fetal epididymis exhibited extensive ERalpha and ERbeta immunostaining at mid- and late gestation. In contrast to the robust expression of ERbeta, androgen receptor protein was not demonstrable within the cells of the seminiferous cords but was abundantly expressed in epididymal epithelial cells of the fetal baboon. In summary, the results of this study show that the fetal baboon testis and epididymis expressed the ERalpha and ERbeta, and we suggest that our nonhuman primate baboon model can be used to study the potential role of estrogen on maturation of the fetal testis.
虽然对转基因小鼠的研究表明雌激素对睾丸发育很重要，但关于雌激素在灵长类胎儿睾丸成熟中的潜在作用却知之甚少。因此，作为确定雌激素是否调节灵长类胎儿睾丸成熟的第一步，我们采用免疫细胞化学方法来确定雌激素受体（ER）α和β在狒狒胎儿睾丸中的表达。其次，我们建立了通过竞争性逆转录-聚合酶链反应来定量ERβ mRNA水平的方法，该反应在通过激光捕获显微切割（LCM）从狒狒胎儿睾丸中分离出的支持细胞中进行。在妊娠中期（第100天）和晚期（第165天）（孕期为184天）的狒狒胎儿中，支持细胞、睾丸周细胞和间质细胞的细胞核中ERβ蛋白表达丰富。通过LCM分离的支持细胞核及相关细胞质中，ERβ mRNA水平为0.03阿托摩尔/飞摩尔18S rRNA。在第165天，ERα在生精小管中低水平表达，在睾丸周细胞中中等水平表达。生殖细胞表达的ERα或ERβ蛋白很少，而狒狒胎儿附睾在妊娠中期和晚期表现出广泛的ERα和ERβ免疫染色。与ERβ的强烈表达相反，雄激素受体蛋白在生精索细胞中未检测到，但在狒狒胎儿附睾上皮细胞中大量表达。总之，本研究结果表明狒狒胎儿睾丸和附睾表达ERα和ERβ，我们认为我们的非人灵长类狒狒模型可用于研究雌激素对胎儿睾丸成熟的潜在作用。
