Kikuchi K, Izaike Y, Noguchi J, Furukawa T, Daen F P, Naito K, Toyoda Y
Department of Genetic Resources II, National Institute of Agrobiological Resources, Ibaraki, Japan.
J Reprod Fertil. 1995 Nov;105(2):325-30. doi: 10.1530/jrf.0.1050325.
Changes of histone H1 kinase activity before and after electrical stimulation were connected with the ability of cytoplasm of pig oocytes to be activated parthenogenetically when matured and aged in vitro. Cumulus-oocyte complexes were collected from prepubertal gilts and cultured in a modified Waymouth's MB752/1 medium. The first mature oocytes were observed after 30 h of culture. After 36 h of culture, about 65% of oocytes had matured (reached metaphase II stage with the first polar body). When oocytes matured after 36 h of culture were stimulated with an electric pulse and subsequently cultured for 10 h, only 7% became parthenogenetically activated (formation of a female pronucleus). When oocytes matured for 60 h and 72 h underwent the same treatment, significantly more became activated parthenogenetically (46% and 57%, respectively). Oocytes matured for 72 h but not stimulated electrically also exhibited high spontaneous parthenogenetic activation (24%). Activation of oocytes resulted either in the formation of a female pronucleus(ei) or in fragmentation of oocytes. Fragmentation in stimulated and nonstimulated oocytes increased significantly after 72 h of culture (37% and 18%, respectively). Histone H1 kinase activity in immature oocytes at the germinal vesicle stage was low (17.2 fmol h-1 per oocyte). However, when oocytes were cultured for 36 and 48 h, histone H1 kinase activity increased significantly (168.2 and 138.5 fmol h-1 per oocyte, respectively). Prolonged culture (60 h and 72 h) resulted in a significant decrease in histone H1 kinase activity (94.3 and 49.3 fmol h-1 per oocyte, respectively). When oocytes cultured for up to 72 h were electrically stimulated, histone H1 kinase activity in activated oocytes (oocytes that formed a female pronucleus and fragmented oocytes) was significantly lower (24.7 mol h-1 per oocyte) than that in nonactivated oocytes (99.9 mol h-1 per oocyte). The present data clearly indicate that the gradual decrease of histone H1 kinase activity is correlated with ageing of oocytes matured in vitro and with their ability to be parthenogenetically activated.
体外成熟和老化的猪卵母细胞，其细胞质孤雌激活能力与电刺激前后组蛋白H1激酶活性的变化相关。从青春期前的后备母猪采集卵丘 - 卵母细胞复合体，并在改良的Waymouth's MB752/1培养基中培养。培养30小时后观察到第一批成熟卵母细胞。培养36小时后，约65%的卵母细胞成熟（达到带有第一极体的中期II期）。当对培养36小时后成熟的卵母细胞进行电脉冲刺激并随后培养10小时时，只有7%的卵母细胞发生孤雌激活（形成雌原核）。当对培养60小时和72小时后成熟的卵母细胞进行相同处理时，发生孤雌激活的卵母细胞明显增多（分别为46%和57%）。培养72小时但未进行电刺激的卵母细胞也表现出较高的自发孤雌激活率（24%）。卵母细胞的激活要么导致雌原核的形成，要么导致卵母细胞破碎。培养72小时后，受刺激和未受刺激的卵母细胞中的破碎率显著增加（分别为37%和18%）。生发泡期未成熟卵母细胞中的组蛋白H1激酶活性较低（每个卵母细胞17.2 fmol h-1）。然而，当卵母细胞培养36小时和48小时时，组蛋白H1激酶活性显著增加（分别为每个卵母细胞168.2和138.5 fmol h-1）。延长培养时间（60小时和72小时）导致组蛋白H1激酶活性显著降低（分别为每个卵母细胞94.3和49.3 fmol h-1）。当对培养长达72小时的卵母细胞进行电刺激时，激活的卵母细胞（形成雌原核的卵母细胞和破碎的卵母细胞）中的组蛋白H1激酶活性（每个卵母细胞24.7 mol h-1）显著低于未激活的卵母细胞（每个卵母细胞99.9 mol h-1）。目前的数据清楚地表明，组蛋白H1激酶活性的逐渐降低与体外成熟卵母细胞的老化及其孤雌激活能力相关。
