Hamad Shaimaa K, Elomda Ahmed M, Sun Yanyan, Li Yunlei, Zong Yunhe, Chen Jilan, Abbas Ahmed O, Stino Farid K R, Nazmi Ali, Mehaisen Gamal M K
Department of Animal Production, Faculty of Agriculture, Cairo University, Giza 12613, Egypt.
Department of Animal Sciences, The Ohio State University, Columbus, OH 43210, USA.
Animals (Basel). 2023 May 11;13(10):1603. doi: 10.3390/ani13101603.
Sperm cryopreservation is an effective technique for conserving animal genetic diversity and transmitting superior genetic backgrounds, maintained via a non-invasive sampling and collection of huge quantities of sperm. Nevertheless, cryopreservation in avian species is not commercially viable because of the rooster sperm's susceptibility to damage. This study aims to estimate the impact of dimethylacetamide (DMA) as a cryoprotectant at different levels (3%, 6%, or 9%) on the post-thawed sperm quality, motility, antioxidant-biomarkers, and the expression of anti-freeze related genes. Semen samples were collected twice a week from twelve roosters aged 40 wk, weighing 3400 ± 70 g, and belonging to the Cairo-B2 chicken strain. Fresh semen samples were rapidly appraised, pooled, diluted with two volumes of a basic extender, and divided equally into three groups. The diluted groups were chilled at -20 °C for 7 min, then gently supplemented with 3, 6, or 9% pre-cooled DMA and equilibrated at 5 °C for a further 10 min. Semen pellets were formed by pipetting drops 7 cm above liquid nitrogen (LN), which were then kept inside cryovials in the LN. Thawing was performed 2 months later by taking 3-4 pellets of the frozen semen into a glass tube and warming it in a water bath for 8 s at 60 °C. The results showed that 3% DMA increased the proportion of total motile sperm, progressivity, viability, and plasma membrane integrity (%) compared to the 6% and 9% DMA groups. The lipid peroxidation and antioxidant enzyme activity were improved in the 3% group. At the same time, some anti-freeze-related genes' (including ras homolog family member A (RHOA), heat shock protein 70 (HSP70), and small nuclear ribonucleoprotein polypeptide A (SNRPA1)) expressions were upregulated within the 3% DMA group relative to other groups. In conclusion, the 3% DMA group maintained higher post-thawed sperm quality than the other tested groups.
精子冷冻保存是一种保护动物遗传多样性和传递优良遗传背景的有效技术，通过非侵入性采样和采集大量精子来维持。然而，由于公鸡精子易受损伤，禽类的冷冻保存不具有商业可行性。本研究旨在评估不同浓度（3%、6%或9%）的二甲基乙酰胺（DMA）作为冷冻保护剂对解冻后精子质量、活力、抗氧化生物标志物以及抗冻相关基因表达的影响。每周从12只40周龄、体重3400±70克、属于开罗 - B2鸡品系的公鸡采集两次精液样本。新鲜精液样本迅速进行评估、混合，用两倍体积的基础稀释液稀释，并平均分为三组。稀释后的组在-20°C下冷冻7分钟，然后轻轻加入3%、6%或9%预冷的DMA，并在5°C下再平衡10分钟。通过在液氮（LN）上方7厘米处滴加精液形成精液颗粒，然后将其保存在LN中的冻存管内，并于2个月后进行解冻，将3 - 4个冷冻精液颗粒放入玻璃管中，在60°C的水浴中加热8秒。结果表明，与6%和9% DMA组相比，3% DMA提高了总活动精子比例、前进性、活力和质膜完整性（%）。3%组的脂质过氧化和抗氧化酶活性得到改善。同时，相对于其他组，3% DMA组中一些抗冻相关基因（包括Ras同源家族成员A（RHOA）、热休克蛋白70（HSP70）和小核核糖核蛋白多肽A（SNRPA1））的表达上调。总之，3% DMA组解冻后的精子质量高于其他测试组。
