Lennard S N, Stewart F, Allen W R
Thoroughbred Breeders' Association Equine Fertility Unit, Mertoun Paddocks, Suffolk, United Kingdom.
Mol Reprod Dev. 1995 Oct;42(2):131-40. doi: 10.1002/mrd.1080420202.
In situ hybridization, Northern blotting, and immunohistochemical techniques were used to study the expression of transforming growth factor beta 1 (TGF beta 1) in the endometrium of the mare during the first 150 days of pregnancy (term = 330-340 days). In situ hybridization using an oligonucleotide (45mer) probe, based on a homologous region within all known mammalian TGF beta 1 DNA sequences, demonstrated TGF beta 1 mRNA accumulation in the glandular and lumenal epithelial cells of the endometrium from day 33 onwards which corresponds to the time of implantation (day 33-45). Expression in the endometrium remained at a high level to the end of the sampling period (day 150). There was also marked expression of TGF beta 1 in the mononuclear cells accumulated around the periphery of the specialized trophoblast cells of the endometrial cup within the endometrium and in the mononuclear cells accumulated in the endometrial stroma of mares carrying failing donkey-in-horse pregnancies created by embryo transfer. The sense (control) oligonucleotide probe exhibited no hybridization to any tissue at any stage. Northern blot analysis demonstrated that the oligonucleotide probe and a porcine TGF beta 1 cDNA clone hybridized to a single 2.5 kb transcript in horse endometrial and lymphocyte RNA, thus validating the oligonucleotide probe for detection of horse TGF beta 1 mRNA. Furthermore, both probes demonstrated an increased signal in the pregnant endometrium from day 33 onwards, thereby confirming the in situ hybridization results. Immunostaining with a specific anti-bovine TGF beta 1 serum also showed increasing TGF beta 1 accumulation in endometrial epithelia during pregnancy, and localization of the protein in endometrial stroma and in the trophoblast layer of the placenta after day 60 of pregnancy. These results show that TGF beta 1 expression increases in the maternal endometrium of the mare at the time of implantation and that it may play a role in regulating endometrial and/or trophoblast growth and differentiation during placentation in this species. It may also influence fetal development (via placental transfer) at a later stage of gestation.
采用原位杂交、Northern印迹和免疫组织化学技术，研究了母马妊娠前150天（孕期=330-340天）子宫内膜中转化生长因子β1（TGFβ1）的表达情况。使用基于所有已知哺乳动物TGFβ1 DNA序列同源区域的寡核苷酸（45聚体）探针进行原位杂交，结果显示从第33天开始，即相当于着床时间（第33-45天），子宫内膜的腺上皮细胞和腔上皮细胞中出现TGFβ1 mRNA积累。在采样期结束（第150天）时，子宫内膜中的表达仍维持在较高水平。在子宫内膜内子宫内膜杯特化滋养层细胞周围聚集的单核细胞中，以及在通过胚胎移植产生的马怀驴失败妊娠母马的子宫内膜基质中聚集的单核细胞中，也有明显的TGFβ1表达。正义（对照）寡核苷酸探针在任何阶段均未与任何组织发生杂交。Northern印迹分析表明，寡核苷酸探针和猪TGFβ1 cDNA克隆与马子宫内膜和淋巴细胞RNA中的单一2.5 kb转录本杂交，从而验证了该寡核苷酸探针可用于检测马TGFβ1 mRNA。此外，两种探针均显示从第33天开始，妊娠子宫内膜中的信号增强，从而证实了原位杂交结果。用特异性抗牛TGFβ1血清进行免疫染色也显示，妊娠期间子宫内膜上皮中TGFβ1积累增加，且在妊娠60天后，该蛋白定位于子宫内膜基质和胎盘的滋养层。这些结果表明，TGFβ1在母马子宫内膜着床时表达增加，并且可能在该物种胎盘形成过程中调节子宫内膜和/或滋养层生长及分化中发挥作用。它也可能在妊娠后期影响胎儿发育（通过胎盘转运）。
