Recuero Sandra, Sánchez José María, Mateo-Otero Yentel, Bagés-Arnal Sandra, McDonald Michael, Behura Susanta K, Spencer Thomas E, Kenny David A, Yeste Marc, Lonergan Pat, Fernandez-Fuertes Beatriz
Biotechnology of Animal and Human Reproduction (TechnoSperm), Department of Biology, Institute of Food and Agricultural Technology, University of Girona, Girona, Spain.
School of Agriculture and Food Science, University College Dublin, Dublin, Ireland.
Front Cell Dev Biol. 2020 Jul 10;8:547. doi: 10.3389/fcell.2020.00547. eCollection 2020.
An appropriate female reproductive environment is essential for pregnancy success. In several species, including mice, pigs and horses, seminal plasma (SP) components have been shown to modulate this environment, leading to increased embryo viability and implantation. Due to the characteristics of mating in the aforementioned species, SP comes into direct contact with the uterus. However, it is questionable whether any SP reaches the uterus in species that ejaculate inside the vagina, such as humans and cattle. Hence, we hypothesized that sperm, perhaps acting as a vehicle for SP factors, play a more important role in the modulation of the maternal uterine environment in these species. In addition, changes elicited by SP and/or sperm may originate in the vagina and propagate to more distal regions of the female reproductive tract. To test these hypotheses, a bovine model in which heifers were mated to intact or vasectomized bulls or were left unmated was used. RNA-sequencing of endometrial samples collected 24 h after mating with a vasectomized bull did not reveal any differentially expressed genes (DEGs) in comparison with control samples. However, the endometrium of heifers mated with intact bulls exhibited 24 DEGs when compared to heifers mated with vasectomized bulls, and 22 DEGs when compared to unmated control heifers. The expression of a set of cytokines (, , , and ) and candidate genes identified in the endometrial RNA-sequencing (, , , , , and ) were assessed by RT-qPCR in the vagina and oviductal ampulla. No differences in expression of these genes were observed between treatments in any region. However, mating to both intact and vasectomized bulls induced an increase in and expression in the vagina compared to the oviduct. These data indicate that sperm, but not secretions from the accessory glands alone, induce modest changes in endometrial gene expression after natural mating in cattle. However, it is not clear whether this effect is triggered by inherent sperm proteins or SP proteins bound to sperm surface at the time of ejaculation.
适宜的雌性生殖环境对于成功受孕至关重要。在包括小鼠、猪和马在内的多个物种中，已证明精浆（SP）成分可调节这种环境，从而提高胚胎活力和着床率。由于上述物种的交配特性，精浆会直接与子宫接触。然而，对于像人类和牛这类在阴道内射精的物种，是否有任何精浆能到达子宫仍存在疑问。因此，我们推测精子或许作为精浆因子的载体，在调节这些物种的母体子宫环境中发挥着更重要的作用。此外，精浆和/或精子引发的变化可能始于阴道，并传播至雌性生殖道的更远端区域。为了验证这些假设，使用了一个牛模型，其中小母牛与未阉割或已阉割的公牛交配，或不进行交配。与对照样本相比，在与已阉割公牛交配24小时后采集的子宫内膜样本的RNA测序未发现任何差异表达基因（DEG）。然而，与与已阉割公牛交配的小母牛相比，与未阉割公牛交配的小母牛的子宫内膜表现出24个差异表达基因，与未交配的对照小母牛相比则有22个差异表达基因。通过RT-qPCR评估了在阴道和输卵管壶腹中一组细胞因子（、、、和）以及在子宫内膜RNA测序中鉴定出的候选基因（、、、、、和）的表达。在任何区域的处理之间均未观察到这些基因表达的差异。然而，与输卵管相比，与未阉割和已阉割公牛交配均诱导阴道中 和 表达增加。这些数据表明，在牛自然交配后，精子而非仅附属腺的分泌物会诱导子宫内膜基因表达发生适度变化。然而，尚不清楚这种效应是由固有精子蛋白还是射精时结合在精子表面的精浆蛋白触发的。
