Abstract

Cervical mucus plays an important role in female fertility, since it allows the entry of motile and morphological normal sperm while preventing the ascent of pathogens from the vagina. The function of cervical mucus is critically linked to its rheological properties that are in turn dictated by O-glycosylated proteins, called mucins. We aimed to characterize the O-glycan composition in the cervical mucus of six European ewe breeds with known differences in pregnancy rates following cervical/vaginal artificial insemination with frozen–thawed semen, which are due to reported differences in cervical sperm transport. These were Suffolk (low fertility) and Belclare (medium fertility) in Ireland, Ile de France and Romanov (both with medium fertility) in France, and Norwegian White Sheep (NWS) and Fur (both with high fertility) in Norway (n = 28–30 ewes/breed). We identified 124 O-glycans, from which 51 were the major glycans with core 2 and fucosylated glycans as the most common structures. The use of exogenous hormones for synchronization did not affect the O-glycan composition in both high-fertility ewe breeds, but it did in the other four ewe breeds. There was a higher abundance of the sulfated glycan (Galβ1–3[SO3-GlcNAcβ1–6]GalNAc), fucosylated glycan (GlcNAcβ1–3(Fucα1–2Galβ1–3)GalNAc) and core 4 glycan (GlcNAcβ1–3[GlcNAcβ1–6]GalNAc) in the low-fertility Suffolk breed compared with NWS (high fertility). In addition, core 4 glycans were negatively correlated with mucus viscosity. This novel study has identified O-glycans that are important for cervical sperm transport and could have applications across a range of species including human.

中文翻译：

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宫颈粘液中 O-连接聚糖作为精子运输生物标志物的鉴定和表征：一种新的绵羊模型

摘要

宫颈粘液在女性生育能力中起着重要作用，因为它允许运动和形态正常的精子进入，同时防止病原体从阴道上升。宫颈粘液的功能与其流变特性密切相关，而流变特性又由称为粘蛋白的O-糖基化蛋白质决定。我们的目标是描述O- 已知在用冻融精液进行宫颈/阴道人工授精后妊娠率存在差异的 6 种欧洲母羊的宫颈粘液中的多糖组成，这是由于报道的宫颈精子运输存在差异。它们是爱尔兰的 Suffolk（低生育率）和 Belclare（中等生育率），法国的 Ile de France 和 Romanov（均中等生育率），以及挪威的挪威白羊 (NWS) 和 Fur（均高生育率）（n  = 28-30 只母羊/品种）。我们鉴定了 124 个O-聚糖，其中 51 个是主要聚糖，核心 2 和岩藻糖基化聚糖是最常见的结构。使用外源性激素进行同步不会影响O高繁殖力母羊品种中的多糖组成，但在其他四个母羊品种中确实如此。硫酸化聚糖 (Galβ1–3[SO3-GlcNAcβ1–6]GalNAc)、岩藻糖基化聚糖 (GlcNAcβ1–3(Fucα1–2Galβ1–3)GalNAc) 和核心 4 聚糖 (GlcNAcβ1–3[GlcNAcβ1–6 ]GalNAc）在低生育力萨福克品种中与 NWS（高生育力）相比。此外，核心 4 聚糖与粘液粘度呈负相关。这项新颖的研究已经确定了对宫颈精子运输很重要的O-聚糖，并且可以在包括人类在内的一系列物种中得到应用。