Laboratory of Reproductive Biology, Institute of Biotechnology of the Czech Academy of Sciences, BIOCEV, Prumyslova 595, 252 50 Vestec, Czech Republic.
Department of Zoology, Faculty of Science, Charles University, BIOCEV, Vinicna 7, 128 44 Prague 2, Czech Republic.
Int J Mol Sci. 2020 Apr 10;21(7):2651. doi: 10.3390/ijms21072651.
Fertilization is a multiple step process leading to the fusion of female and male gametes and the formation of a zygote. Besides direct gamete membrane interaction via binding receptors localized on both oocyte and sperm surface, fertilization also involves gamete communication via chemical molecules triggering various signaling pathways. This work focuses on a mouse taste receptor, mTAS1R3, encoded by the gene, as a potential receptor mediating chemical communication between gametes using the C57BL/6J lab mouse strain. In order to specify the role of mTAS1R3, we aimed to characterize its precise localization in testis and sperm using super resolution microscopy. The testis cryo-section, acrosome-intact sperm released from and sperm which underwent the acrosome reaction (AR) were evaluated. The mTAS1R3 receptor was detected in late spermatids where the acrosome was being formed and in the acrosomal cap of acrosome intact sperm. AR is triggered in mice during sperm maturation in the female reproductive tract and by passing through the egg surroundings such as cells. This AR onset is independent of the extracellular matrix of the oocyte called . After AR, the relocation of mTAS1R3 to the equatorial segment was observed and the receptor remained exposed to the outer surroundings of the female reproductive tract, where its physiological ligand, the amino acid , naturally occurs. Therefore, we targeted the possible interaction in vitro between the mTAS1R3 and as a part of chemical communication between sperm and egg and used an anti-mTAS1R3-specific antibody to block it. We detected that the acrosome reacted spermatozoa showed a chemotactic response in the presence of during and after the AR, and it is likely that mTAS1R3 acted as its mediator.
受精是一个多步骤的过程，导致雌性和雄性配子的融合，并形成一个受精卵。除了通过结合位于卵母细胞和精子表面的受体直接进行配子膜相互作用外，受精还涉及通过触发各种信号通路的化学分子进行配子间的通讯。本工作专注于一种小鼠味觉受体 mTAS1R3，它由 基因编码，作为一种潜在的受体，利用 C57BL/6J 实验小鼠品系介导配子间的化学通讯。为了明确 mTAS1R3 的作用，我们旨在使用超分辨率显微镜来描述其在睾丸和精子中的精确定位。评估了睾丸冷冻切片、从 中释放的顶体完整精子和经历顶体反应 (AR) 的精子。mTAS1R3 受体在正在形成顶体的晚期精母细胞和顶体完整精子的顶体帽中被检测到。在雌性生殖道中精子成熟期间以及通过穿过卵周围的细胞如 细胞时，在小鼠中触发 AR。这种 AR 的开始与卵的细胞外基质 无关。在 AR 之后，观察到 mTAS1R3 向赤道段的重新定位，并且该受体仍然暴露于雌性生殖道的外部环境中，其生理配体，氨基酸 ，自然存在于该环境中。因此，我们针对 mTAS1R3 和 之间的可能相互作用进行了体外研究，作为精子和卵子之间化学通讯的一部分，并使用抗 mTAS1R3 特异性抗体来阻断它。我们发现，在 AR 期间和之后，在 存在的情况下，顶体反应的精子显示出趋化反应，并且 mTAS1R3 可能作为其介导物。
