Université Paris-Saclay, UVSQ, INRAE, BREED, Jouy-en-Josas, France.
Ecole Nationale Vétérinaire d'Alfort, BREED, Maisons-Alfort, France.
Biol Reprod. 2021 Apr 1;104(4):794-805. doi: 10.1093/biolre/ioab005.
The success of embryo development and implantation depends in part on the environment in which the embryo evolves. However, the composition of the uterine fluid surrounding the embryo in the peri-implantation period remains poorly studied. In this work, we aimed to develop a new strategy to visualize, collect, and analyze both blastocoelic liquid and juxta-embryonic uterine fluid from in vivo peri-implantation rabbit embryos. Using high-resolution ultrasound biomicroscopy, embryos were observed as fluid-filled anechoic vesicles, some of which were surrounded by a thin layer of uterine fluid. Ultrasound-guided puncture and aspiration of both the blastocoelic fluid contained in the embryo and the uterine fluid in the vicinity of the embryo were performed. Using nuclear magnetic resonance spectroscopy, altogether 24 metabolites were identified and quantified, of which 21 were detected in both fluids with a higher concentration in the uterus compared to the blastocoel. In contrast, pyruvate was detected at a higher concentration in blastocoelic compared to uterine fluid. Two acidic amino acids, glutamate and aspartate, were not detected in uterine fluid in contrast to blastocoelic fluid, suggesting a local regulation of uterine fluid composition. To our knowledge, this is the first report of simultaneous analysis of blastocoelic and uterine fluids collected in vivo at the time of implantation in mammals, shedding new insight for understanding the relationship between the embryo and its local environment at this critical period of development.
胚胎发育和着床的成功部分取决于胚胎发育所处的环境。然而，着床期围绕胚胎的子宫液的组成仍未得到充分研究。在这项工作中，我们旨在开发一种新策略，以可视化、收集和分析体内着床期兔胚胎的囊胚腔液和胚胎旁的子宫液。使用高分辨率超声生物显微镜，胚胎被观察为充满液体的无回声囊泡，其中一些被一层薄的子宫液包围。对胚胎内的囊胚腔液和胚胎附近的子宫液进行超声引导下的穿刺和抽吸。使用核磁共振波谱法，共鉴定和定量了 24 种代谢物，其中 21 种在两种液体中均有检测，且在子宫中浓度高于囊胚腔。相比之下，丙酮酸在囊胚腔中的浓度高于子宫液。两种酸性氨基酸，谷氨酸和天冬氨酸，在子宫液中未被检测到，而在囊胚腔液中被检测到，提示子宫液组成存在局部调节。据我们所知，这是首次在哺乳动物着床时同时分析体内收集的囊胚腔液和子宫液，为理解胚胎及其局部环境在这一关键发育时期的关系提供了新的认识。
