Kumar Dharmendra, Kumar Pradeep, Singh Pawan, Yadav S P, Yadav P S
Animal Physiology and Reproduction Division, ICAR-Central Institute for Research on Buffaloes, Sirsa Road, Hisar, 125001, Haryana, India.
ICAR-National Dairy Research Institute, Karnal, 132001, Haryana, India.
Cytotechnology. 2016 May;68(3):451-8. doi: 10.1007/s10616-014-9798-9. Epub 2014 Nov 6.
The present study was designed to investigate the sperm damages occurring in acrosome, plasma membrane, mitochondrial activity, and DNA of fresh, equilibrated and frozen-thawed buffalo semen by fluorescent probes. The stability of sperm acrosome and plasma membrane stability, mitochondrial activity and DNA status were assessed by fluorescein conjugated lectin Pisum sativum agglutinin, Annexin-V/propidium iodide, JC-1 and TUNEL assay, respectively, under the fluorescent microscope. The damages percentage of acrosome integrity was significantly increased during equilibration and freezing-thawing process. The stability of sperm plasma membrane is dependent on stability of phosphatidylserine (PS) on the inner leaflet of plasma membrane. The frozen-thawed sperm showed externalization of PS leading to significant increase in apoptotic, early necrotic and necrotic changes and lowered high mitochondrial membrane potential as compared with the fresh sperm but all these parameters were not affected during equilibration. However, the DNA integrity was not affected during equilibration and freezing-thawing procedure. In conclusion, the present study revealed that plasma membrane and mitochondria of buffalo sperm are more susceptible to damage during cryopreservation. Furthermore, the use of fluorescent probes to evaluate integrity of plasma and acrosome membranes, as well as mitochondrial membrane potential and DNA status increased the accuracy of semen analyses.
本研究旨在通过荧光探针研究新鲜、平衡和冻融后的水牛精液在顶体、质膜、线粒体活性和DNA方面发生的精子损伤。在荧光显微镜下,分别用荧光素偶联的凝集素豌豆凝集素、膜联蛋白V/碘化丙啶、JC-1和TUNEL检测法评估精子顶体稳定性、质膜稳定性、线粒体活性和DNA状态。在平衡和冻融过程中,顶体完整性的损伤百分比显著增加。精子质膜的稳定性取决于质膜内小叶上磷脂酰丝氨酸(PS)的稳定性。与新鲜精子相比,冻融后的精子显示PS外化,导致凋亡、早期坏死和坏死变化显著增加,线粒体膜电位降低,但所有这些参数在平衡过程中均未受影响。然而,在平衡和冻融过程中,DNA完整性未受影响。总之,本研究表明,水牛精子的质膜和线粒体在冷冻保存过程中更容易受到损伤。此外,使用荧光探针评估质膜和顶体膜的完整性以及线粒体膜电位和DNA状态提高了精液分析的准确性。