Although reduced reproductive efficiency during summer has been well documented in buffaloes, the reason for the same is yet to be understood. The present study was conducted to identify the subtle differences in sperm phenotypic characteristics (motility, membrane integrity, acrosome reaction and lipid peroxidation status), oviduct binding ability and expression of fertility‐associated genes (AK 1, ATP5D, CatSper 1, Cytochrome P450 aromatase, SPP1 and PEBP1) between winter and summer seasons in buffaloes. Cryopreserved spermatozoa from 6 Murrah buffalo bulls (3 ejaculates/bull/season) were utilized for the study. Real‐time quantitative PCR was performed for assessing the expression patterns of select fertility‐associated genes. The proportion of motile and membrane intact spermatozoa was significantly higher (p < .05) in winter as compared to summer ejaculates. The proportion of moribund and lipid peroxidized spermatozoa was significantly lower (p < .05) in winter ejaculates as compared to summer. The sperm‐oviduct binding index was significantly lower (p < .01) when spermatozoa from summer ejaculates were used as compared to winter ejaculates. The expression of fertility‐associated genes did not differ significantly between the two seasons except for PEPB1; the transcriptional abundance of PEPB1 was significantly (p < .05) lower in summer as compared to winter season. It was inferred that buffalo spermatozoa produced during winter season were superior in terms of cryotolerance, membrane and acrosome integrity, lipid peroxidation status and the ability to bind with oviduct explants.

中文翻译：

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冬季产生的精子在水牛（Bubalus bubalis）的表型特征和输卵管外植体的结合能力方面表现优异。

尽管在水牛中已充分证明了夏季繁殖效率降低的原因，但其原因尚待了解。本研究旨在确定精子表型特征（运动性，膜完整性，顶体反应和脂质过氧化状态），输卵管结合能力和与生育相关的基因（AK 1，ATP5D，CatSper 1，细胞色素P450芳香化酶）的表达之间的细微差异。 ，SPP1和PEBP1）在水牛的冬季和夏季之间。研究使用了来自6头Murrah水牛公牛（3枚射精/公牛/季节）的冷冻保存的精子。进行了实时定量PCR，以评估与生育力相关的特定基因的表达模式。运动和完整膜精子的比例明显更高（p <.05），而夏季则射精。 与夏季相比，冬季射精的垂死性和脂质过氧化精子的比例显着降低（p <.05）。 与冬季射精相比，使用夏季射精的精子时精子输卵管结合指数显着较低（p <.01）。与生育力相关的基因的表达在两个季节之间没有显着差异，除了PEPB1。PEPB1的转录丰度显着（p <.05）夏季比冬季低。可以推断，冬季产生的水牛精子在耐寒性，膜和顶体完整性，脂质过氧化状态以及与输卵管外植体结合的能力方面均优越。