Program of Food and AgriLife Science, Graduate School of Integrated Sciences for Life, Hiroshima University, 1-4-4 Kagamiyama, Higashi-Hiroshima City, Hiroshima, 739-8528, Japan.
Department of Life Sciences, Faculty of Life and Environmental Science, Shimane University, 1060 Nishikawatsu-cho, Matsue, Shimane 690-8504, Japan.
Anim Reprod Sci. 2021 Apr;227:106731. doi: 10.1016/j.anireprosci.2021.106731. Epub 2021 Feb 20.
In birds, the ejaculated spermatozoa do not directly pass to the site of fertilization but rather are stored initially in specialized structures, referred to as sperm storage tubules (SSTs), located in the utero-vaginal junction (UVJ) of the oviduct. The fertilizing capacity of spermatozoa in the SSTs is maintained for an extended period (i.e., several days to months). Although many studies have been conducted to ascertain the mechanisms involved in sperm storage, the understanding of the phenomenon is limited. In this study, there was investigation of the effects of sperm surface oligosaccharides in sperm passage into SSTs in Japanese quail. Results from lectin staining of ejaculated spermatozoa indicated galactose/N-Acetylgalactosamine (Gal/GalNAc), N-Acetylglucosamine (GlcNAc) or mannose/glucose (Man/Glc) moieties were present on the sperm surface, indicating the presence of glycoproteins/glycolipids containing these oligosaccharides. When ejaculated spermatozoa were co-incubated with UVJ explants, the lectins derived from Agaricus bisporus and Canavalia ensiformis had marked inhibitory effects on sperm passage into SSTs. Preincubation of UVJ explants with these lectins, however, had no effect indicating there were no effects of UVJ oligosaccharides in this process. Furthermore, none of these lectin had effects on values of sperm motility variables. These results indicate that O-glycans with terminal β-Gal or GalNAc and N-glycans with terminal α-D-Man or α-D-Glc may have functions in the process of sperm passage into SSTs.
在鸟类中，射出的精子不是直接到达受精部位，而是最初储存在输卵管的子宫-阴道交界处（UVJ）的专门结构中，称为精子储存管（SST）。SST 中的精子的受精能力可以维持很长一段时间（即几天到几个月）。尽管已经进行了许多研究来确定精子储存所涉及的机制，但对该现象的理解仍然有限。在这项研究中，研究了日本鹌鹑精子表面寡糖在精子进入 SST 中的作用。对射出的精子进行凝集素染色的结果表明，精子表面存在半乳糖/N-乙酰半乳糖胺（Gal/GalNAc）、N-乙酰葡萄糖胺（GlcNAc）或甘露糖/葡萄糖（Man/Glc）部分，表明存在含有这些寡糖的糖蛋白/糖脂。当射出的精子与 UVJ 外植体共同孵育时，来自双孢蘑菇和刀豆的凝集素对精子进入 SST 有明显的抑制作用。然而，预先孵育 UVJ 外植体与这些凝集素没有影响，表明在这个过程中 UVJ 寡糖没有影响。此外，这些凝集素对精子运动变量的值均没有影响。这些结果表明，具有末端β-Gal 或 GalNAc 的 O-聚糖和具有末端α-D-Man 或α-D-Glc 的 N-聚糖可能在精子进入 SST 的过程中发挥作用。
