猪卵泡液和胎牛血清对猪小腔卵泡卵母细胞体外成熟的影响

本研究探讨了猪卵泡液(pFF)和胎牛血清(FCS)对猪小腔卵泡卵母细胞体外成熟的影响。将猪小腔卵泡(直径<2mm)卵母细胞-卵丘复合体(COCs)以15～35枚为一组随机置于添加不同浓度(0、5%、10%、20%)pFF(试验一)或不同浓度(0、5%、10%、20%)FCS(试验二)的改良TCM-199成熟液中培养44～48h,观察卵母细胞的核成熟率和卵丘扩散情况。试验一结果显示,成熟液中添加10%pFF与对照组和添加5%、20%pFF组相比,显著提高猪小腔卵泡卵母细胞的核成熟率(28 2%比20 5%、20 9%、22 3%;p<0 05);添加5%和20%pFF组与对照组相比,它们的小腔卵泡卵母细胞核成熟率之间差异不显著(p>0 05);添加5%pFF组的COCs卵丘细胞呈现第3类扩散,添加10%和20%pFF组的COCs卵丘细胞呈现第4类扩散,而不添加pFF的对照组的COCs卵丘细胞呈现第2类扩散。试验二结果显示,成熟液中添加10%FCS与对照组和添加5%、20%FCS组相比,明显提高猪小腔卵泡卵细胞的核成熟率(60 0%比37 5%、40 2%、43 9%;p<0 05);添加5%和20%FCS组与对照组相比,它们的小腔卵泡卵细胞核成熟率之间差异不显著(p<0 05);FCS在COCs体外成熟培养的前22～24h促进了卵丘扩散(3个处理组的COCs卵丘细胞呈现第3类扩散,而对照组COCs的卵丘细胞呈现第2类扩散)。研究结果表明:(1)成熟液中添加pFF可促使猪小

Effects of porcine follicular fluid and fetal calf serum on in vitro maturation of porcine oocytes derived from small follicles

The objective of the present study was to examine the effects of porcine follicular fluid (pFF) and fetal calf serum (FCS) on in vitro maturation of porcine oocytes derived from small follicles (diameter <2 mm). Groups of 15～30 porcine cumulus-oocyte complexes (COCs) derived from small follicles were randomly cultured in modified TCM-199 medium supplemented with different concentrations (0, 5%, 10% and 20%) of pFF (Expt. 1) or FCS (Expt. 2) for 44～48 hours. Nuclear maturation rates of oocytes and the degrees of cumulus expansion were examined at the end of culture. Results of Expt. 1 showed that: (1) comparing with supplementations of 0%, 5% and 20% pFF, supplementation of 10% pFF in maturation medium significantly improved the nuclear maturation rate of porcine oocytes (28.2% vs 20.5%, 20.9% and 22.3%; p<0.05), while the nuclear maturation rates of porcine oocytes cultured in maturation medium supplemented with 0, 5% and 20% pFF were not significantly different (p>0.05); (2) COCs in the groups of 10% and 20% pFF supplementation showed category 4 cumulus expansion, and COCs in the group of 5% pFF supplementation showed category 3 cumulus expansion, while COCs in the control showed category 2 cumulus expansion. Results of Expt. 2 showed that: (1) comparing with supplementations of 0%, 5% and 20% FCS, supplementation of 10% FCS in maturation medium significantly improved the nuclear maturation rate of porcine oocytes (60.0% vs 37.5%, 40.2% and 43.9%; p<0.05), while the nuclear maturation rates of porcine oocytes cultured in maturation medium supplemented with 0, 5% and 20% FCS were not significantly different (p>0.05); (2) in the first 22～24 hours of culture, addition of FCS improved cumulus expansion of porcine COCs (COCs in the groups of 5%, 10%, 20% FCS supplementation showed category 3 cumulus expansion while COCs in the control showed category 2 cumulus expansion), but in the second 22～24 hours of culture the expanded cumulus cells contracted. It was concluded that: (1) supplementation of a certain amount (10%) of pFF or FCS to maturation medium can improve nuclear maturation of porcine oocytes derived from small follicles; (2) pFF can enhance cumulus expansion of porcine COCs derived from small follicles; (3) nuclear maturation of porcine oocytes derived from small follicles is not necessarily related to cumulus cells expansion.