Kumaresan A, Johannisson A, Bergqvist A-S
Division of Reproduction, Department of Clinical Sciences, Faculty of Veterinary Medicine and Animal Science, Swedish University of Agricultural Sciences, PO Box 7054, SE-750 07 Uppsala, Sweden.
Reprod Fertil Dev. 2017 Jun;29(6):1096-1106. doi: 10.1071/RD15474.
Spermatozoa undergo several modifications in the oviduct before acquiring fertilising capacity. Although spermatozoa are exposed to similar conditions in the oviduct, the speed of the response varies with the male and the state of the spermatozoa. We hypothesised that spermatozoa from bulls with different fertility may differ in their ability to respond to oviductal fluid (ODF). Frozen-thawed spermatozoa from four bulls were incubated with oestrus oviductal fluid (OODF) for 6h. Sperm kinematics, tyrosine phosphorylation, phosphorylation patterns, capacitation and acrosome reaction were analysed at hourly intervals. The amplitude of lateral head displacement (ALH) and straightness coefficient (STR) were higher (P<0.05) in bulls with higher fertility compared with those with lower fertility, at 1-4h of incubation. At 4h of incubation and onwards, spermatozoa from bulls with higher fertility showed a lower degree (P<0.05) of tyrosine phosphorylation and higher degree of capacitation and acrosome reaction. At least five tyrosine-phosphorylated sperm proteins were detected in all bulls. However, the expression of two phosphorylated sperm proteins (183 and 109 kDa) was upregulated in bulls with lower fertility. It may be concluded that cryopreserved spermatozoa from high- and low- fertile bulls differ in their ability to respond to OODF. This may help in developing tools for assessing fertility of bulls, once validated in more animals.
精子在输卵管中经历多次修饰后才获得受精能力。尽管精子在输卵管中面临相似的条件，但反应速度因雄性个体和精子状态而异。我们推测，不同生育能力公牛的精子对输卵管液（ODF）的反应能力可能不同。将来自四头公牛的冻融精子与发情期输卵管液（OODF）孵育6小时。每隔一小时分析精子运动学、酪氨酸磷酸化、磷酸化模式、获能和顶体反应。在孵育1-4小时时，生育能力较高的公牛的侧向头部位移幅度（ALH）和直线性系数（STR）高于（P<0.05）生育能力较低的公牛。在孵育4小时及以后，生育能力较高的公牛的精子酪氨酸磷酸化程度较低（P<0.05），获能和顶体反应程度较高。在所有公牛中均检测到至少五种酪氨酸磷酸化的精子蛋白。然而，两种磷酸化精子蛋白（183和109 kDa）的表达在生育能力较低的公牛中上调。可以得出结论，高生育力和低生育力公牛的冷冻保存精子对OODF的反应能力不同。一旦在更多动物中得到验证，这可能有助于开发评估公牛生育力的工具。
