Faillace L S, Hunter M G
Department of Physiology and Environmental Science, Faculty of Agricultural and Food Sciences, University of Nottingham, Leics, UK.
J Reprod Fertil. 1994 Aug;101(3):571-6. doi: 10.1530/jrf.0.1010571.
A study was carried out to compare preovulatory ovarian events in prolific Meishan gilts (which have high levels of embryo survival) with contemporary white hybrid control gilts. Gilts of similar reproductive ages (second or third oestrous cycle) were observed three times a day for oestrous behaviour and ovaries recovered at a time estimated as within 7 h of ovulation (white hybrid, n = 13; Meishan, n = 16). Preovulatory follicles were recovered (n = 195, white hybrid; n = 252, Meishan), and oocytes were aspirated and fixed for later identification of meiotic stage, and follicular fluid was frozen for subsequent determination of progesterone. The number of presumed ovulatory follicles recovered per animal was similar to the expected ovulation rate (15.0, white hybrid; 15.75, Meishan; P > 0.1); however, follicles from Meishan gilts were smaller (8.1 versus 9.0 mm, P < 0.001) and contained less follicular fluid (139.9 versus 187.6 microliters, P < 0.02) than did white hybrid gilts. Total follicular progesterone (88.7 ng per follicle, white hybrid; 77.4 ng per follicle, Meishan) and concentration of progesterone in follicular fluid (526 ng ml-1, white hybrid; 640 ng ml-1, Meishan) did not differ between the two breeds (P > 0.1). There were no breed differences in the extent of heterogeneity in follicular diameter, volume of follicular fluid, and total follicular progesterone and progesterone concentration (P > 0.1). However, classification of recovered oocytes into seven discrete meiotic stages revealed that more oocytes recovered from Meishan preovulatory follicles were in the more advanced stages of meiosis than were those recovered from white hybrid gilts (P < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)
开展了一项研究，以比较多产的梅山母猪（胚胎存活率高）与同期白色杂交对照母猪排卵前的卵巢事件。每天三次观察生殖年龄相似（第二或第三个发情周期）的母猪的发情行为，并在估计排卵后7小时内回收卵巢（白色杂交母猪，n = 13；梅山母猪，n = 16）。回收排卵前卵泡（白色杂交母猪n = 195；梅山母猪n = 252），吸出卵母细胞并固定，以便随后确定减数分裂阶段，卵泡液冷冻以备后续测定孕酮。每头动物回收的假定排卵卵泡数量与预期排卵率相似（白色杂交母猪为15.0；梅山母猪为15.75；P>0.1）；然而，梅山母猪的卵泡比白色杂交母猪的卵泡小（8.1对9.0毫米，P<0.001），且卵泡液较少（139.9对187.6微升，P<0.02）。两个品种之间卵泡总孕酮（白色杂交母猪每个卵泡88.7纳克；梅山母猪每个卵泡77.4纳克）和卵泡液中孕酮浓度（白色杂交母猪526纳克/毫升；梅山母猪640纳克/毫升）没有差异（P>0.1）。卵泡直径、卵泡液体积、卵泡总孕酮和孕酮浓度的异质性程度在两个品种之间没有差异（P>0.1）。然而，将回收的卵母细胞分类为七个离散的减数分裂阶段后发现，从梅山排卵前卵泡中回收的卵母细胞比从白色杂交母猪中回收的卵母细胞处于减数分裂更高级阶段的更多（P<0.001）。（摘要截断于250字）
