不同浓度二甲双胍对猪精液液态保存效果的影响

[目的]研究不同浓度二甲双胍对猪精液液态保存效果的影响。[方法]在猪精液液态保存液中分别添加不同浓度(0.5、1.0、2.0、4.0 mmol/L)的二甲双胍,测定不同保存时间精子的活力、活率、质膜完整率、顶体完整率等指标。[结果]猪精液液态保存第3天,在不同浓度二甲双胍作用下各组间精子活力出现差异。第5天,添加1.0 mmol/L二甲双胍的保存液保存的精子活力达到38.03%,精子活率为49.03%,质膜完整率为43.91%,顶体完整率为50.88%,均高于对照组。[结论]添加二甲双胍有助于提高液态保存猪精液的质量,延长保存时间。

Development of the SCNT Embryo from Butyrolactone Ⅰ Prematured Bovine Oocytes

The somatic cell nuclear transfer （SCNT） technique has been applied successfully in a range of mammalian species giving rise to offspring, however, the efficiency of development to term has remained low. Oocyte meiotic arrest is an important option to make the SCNT more flexible and increase the number of cloned embryos produced. This paper showed that the use of butyrolactone I to arrest the meiotic division for 24 h prior to in vitro maturation （IVM） provided bovine oocytes capability of supporting development of blastocysts as efficiently as non arrested oocytes. In the SCNT group, cleavage rates were not affected by prematuration when adding butyrolactone I during IVM （57.9% vs. 62.4%; control vs. 10 μmol.L^-1 butyrolactone I）, developmental rates to biastocyst were unaffected （22.0% vs. 20.3%; control vs. 10 μmol.L^-1 butyrolactone I, p〉0.05） by the addition ofbutyrolactone I during IVM in cloned embryos. Moreover, the total cell numbers of blastocyst were not affected by butyrolactone I （total nucleus numbers, 132±16.5 vs. 128±19.4, p〉0.05）. In conclusion, the SCNT embryos from butyrolactone I- prematured bovine oocytes had the same developmental potential as the non treated one. The present study provided a method for laboratories of in vitro embryos production, mainly those working on the SCNT, where prematuration could be used to iiacrease the flexibility of the procedure.

氢化可的松对保存过程中猪精子的影响

动物长期处于应激状态会影响其生育能力。应激对雄性动物生殖影响的研究多在体内进行,但在体外研究甚少,因此本试验在体外添加糖皮质激素研究其对猪精子各项生理指标的影响。试验首先在液态保存中分别添加不同质量浓度的氢化可的松(0.1,0.25,0.5,10.0,50.0 mg/L),检测其对猪精子活力的影响。结果显示,从0.25 mg/L应激质量浓度氢化可的松开始精子活力逐渐下降且均低于对照组(P<0.05)。之后通过蛋白质印迹法在射出的猪精子中证明存在糖皮质激素受体(glucocorticoid receptor,GR)。免疫荧光检测表明GR主要在精子顶体后区及尾部中段表达。精子保存第5天时,氢化可的松+米非司酮处理组精子活力显著高于氢化可的松单独处理组(P<0.05)。随后又检测了长期(5 d)处于应激质量浓度氢化可的松作用下,精子DNA碎裂(DFI)、线粒体膜电位(MMP)、精子凋亡水平。结果表明,精子DFI增加,线粒体功能下降,凋亡比例增加,而这些作用可以被米非司酮拮抗。因此表明氢化可的松可能是通过与其受体GR结合干扰线粒体功能而影响猪精子。