Abstract：
It is important to note that seasonality could affect ram reproductive parameters, and therefore, fertility results after artificial insemination. In this work, 1) we assessed fertility rates after cervical artificial insemination of 11,805 ewes at the beginning (June 21st to July 20th) and at the end (November 20th to December 21st) of the reproductive season in the Assaf breed for the last four years, and 2) we aimed to identify male factors influencing the different reproductive success obtained depending on the time at the mating season in which ovine artificial insemination was performed. For this purpose, we evaluated certain ram reproductive and ultrasonographical parameters as well as we performed a multiparametric and proteomic sperm analysis of 6-19 rams at two very distant points in the mating season (July as Early Breeding Season -EBS- and November as Late Breeding Season -LBS-). Rutinary assessments carried out in the ovine reproduction centers (testicular volume, libido, sperm production and mass motility) showed non-significant differences (P ≥ 0.05) between both studied times, as well as the ram ultrasonographic evaluation (Resistive and Pulsatility Index as Doppler parameters; and pixels mean gray level, and hypoechoic areas percentage and density as echotexture parameters). However, at level of sperm functionality, although sperm quality appeared non-significantly lower (P ≥ 0.05) in the EBS, we identified a significantly different (P < 0.05) sperm proteomic profile between the seasonality points. The following proteins were identified with the lowest abundance in the EBS with a fold change > 4, a P = 2.40e-07, and a q = 2.23e-06: Fibrous Sheath-Interacting Protein 2, Disintegrin and Metalloproteinase Domain-Containing Protein 20-like, Phosphoinositide-Specific Phospholipase C, Tektin 5, Armadillo Repeat-Containing Protein 12 Isoform X3, Solute Carrier Family 9B1, Radial Spoke Head Protein 3 Homolog, Pro-Interleukin-16, NADH Dehydrogenase [Ubiquinone] 1 Alpha Subcomplex Subunit 8, Testis, Prostate and Placenta-Expressed Protein, and Acyl Carrier Protein Mitochondrial. In conclusion, while our basic analyses on male and sperm quality showed similar results between the beginning and the end of the breeding season, on a proteomic level we detected a lower expression of sperm proteins linked to the energy metabolism, sperm-oocyte interactions, and flagellum structure in the EBS. Probably, this different protein expression could be related to the lower fertility rate of Assaf ewes after cervical artificial insemination at this time. More importantly, sperm proteins can be used as highly effective molecular markers in predicting sperm fertilization ability related to intraseasonal variations.
摘要：
值得注意的是，季节性可能会影响公羊的繁殖参数，因此,人工授精后的生育结果。在这项工作中,1）我们评估了过去四年中Assaf品种在生殖季节开始（6月21日至7月20日）和结束（11月20日至12月21日）的11,805只母羊的宫颈人工授精后的生育率，和2）我们旨在确定影响根据进行绵羊人工授精的交配季节的时间而获得的不同繁殖成功的男性因素。为此,我们评估了某些公羊繁殖和超声参数，并在交配季节的两个非常遥远的点（7月为早育季节-EBS-和11月为晚育季节-LBS-）对6-19公羊进行了多参数和蛋白质组学精子分析。在绵羊繁殖中心进行的规则评估(睾丸体积，性欲,精子产生和质量运动性）在两个研究时间之间显示无显着差异（P≥0.05），以及ram超声评估(电阻和搏动指数作为多普勒参数；像素平均灰度级，和低回声面积百分比和密度作为回声参数)。然而,在精子功能水平上，尽管在EBS中精子质量似乎没有显着降低（P≥0.05），我们发现季节性点之间的精子蛋白质组谱差异显著(P<0.05)。鉴定出以下蛋白质在EBS中的丰度最低，倍数变化>4，P=2.40e-07，q=2.23e-06：纤维鞘相互作用蛋白2，整合素和含金属蛋白酶结构域的蛋白质20样，磷酸肌醇特异性磷脂酶C,Tektin5，Armadillo重复蛋白12同工型X3，溶质载体家族9B1，放射状头部蛋白3同源物，前白细胞介素-16，NADH脱氢酶[泛醌]1α亚复合物亚基8，睾丸，前列腺和胎盘表达蛋白,和酰基载体蛋白线粒体。总之,虽然我们对雄性和精子质量的基本分析在繁殖季节的开始和结束之间显示出相似的结果，在蛋白质组水平上，我们检测到与能量代谢有关的精子蛋白的表达较低，精子-卵母细胞相互作用，EBS中的鞭毛结构。可能,这种不同的蛋白表达可能与此时宫颈人工授精后Assaf母羊受精率降低有关。更重要的是,精子蛋白可以作为预测精子受精能力的高效分子标记，与基因内变异有关。
