Torner H, Heleil B, Alm H, Ghoneim I M, Srsen V, Kanitz W, Tuchscherer A, Fattouh E M
Research Institute for the Biology of Farm Animals, 18196 Dummerstorf, Germany.
Theriogenology. 2003 Sep 15;60(5):977-87. doi: 10.1016/s0093-691x(03)00099-2.
The aim of the present study was to examine the cumulus morphology and the oocyte chromatin quality of camel cumulus-oocyte complexes (COCs) at the time of recovery, and to monitor changes in oocyte chromatin configuration and apoptosis in cumulus cells from camel COCs during in vitro maturation (IVM) (0, 12, 24, 32, 36, 42, and 48 p.IVM) depending on pregnancy of donors. A total of 1023 COCs were isolated from sliced ovaries after slaughtering of 47 pregnant and 43 non-pregnant camels in an abattoir. The mean number of COCs per donor was 10.3 in pregnant and 12.5 in non-pregnant donors. The cumulus morphology of COCs was independent of the type of donor and was divided in COCs with compact (26.9 and 28%), dispersed (39.3 and 46%), corona radiata cumulus investment (27.9 and 21.7%) and without cumulus (6 and 4.2%), respectively for pregnant and non-pregnant donors. The highest proportion of COCs exhibited dispersed cumulus (P<0.05). Oocytes with meiotic stages of diplotene >50% were found only in compact (55 and 56.5%) and in dispersed COCs (58.4 and 60%), respectively for pregnant and non-pregnant donors. During IVM (0-48h) the first significant onset of specific meiotic stages were different in oocytes from pregnant donors: metaphase 1 (24-32h), metaphase 2 (36-42h), versus oocytes from non-pregnant donors: metaphase 1 (24h), metaphase 2 (32-48h) (P<0.05). The level of apoptotic cells in cumuli of matured COCs increased during IVM and was higher in matured COCs from non-pregnant donors for each time point during IVM (P<0.01). Camel oocytes meiosis during IVM is accompanied by a drastic increase of apoptosis in the surrounding cumulus cells 0-32 and 0-24h during IVM, respectively for pregnant and non-pregnant donors. The oocytes of pregnant camels require 36h of maturation to reach levels of >50% metaphase 2 stage in comparison to oocytes from non-pregnant donors where 32h are sufficient. The earlier onset of apoptosis in the COCs derived from non-pregnant donors possibly determines the faster progression of the oocytes through the final stages of meiosis.
本研究的目的是在回收时检查骆驼卵丘-卵母细胞复合体（COCs）的卵丘形态和卵母细胞染色质质量，并根据供体的妊娠情况监测骆驼COCs在体外成熟（IVM）（IVM后0、12、24、32、36、42和48小时）过程中卵母细胞染色质构型的变化以及卵丘细胞中的凋亡情况。在一家屠宰场宰杀47头怀孕骆驼和43头未怀孕骆驼后，从切片卵巢中分离出总共1023个COCs。怀孕供体每个供体的COCs平均数量为10.3个，未怀孕供体为12.5个。COCs的卵丘形态与供体类型无关，怀孕和未怀孕供体的COCs分别分为紧密型（26.9%和28%）、分散型（39.3%和46%）、放射冠卵丘包裹型（27.9%和21.7%）和无卵丘型（6%和4.2%）。比例最高的COCs表现为分散卵丘（P<0.05）。仅在紧密型（分别为55%和56.5%）和分散型COCs（分别为58.4%和60%）中发现双线期减数分裂阶段>50%的卵母细胞，分别对应怀孕和未怀孕供体。在IVM（0 - 48小时）期间，怀孕供体卵母细胞特定减数分裂阶段的首次显著出现时间不同：中期1（24 - 32小时），中期2（36 - 42小时），而未怀孕供体卵母细胞：中期1（24小时），中期2（32 - 48小时）（P<0.05）。成熟COCs卵丘中凋亡细胞的水平在IVM期间增加，并且在IVM期间的每个时间点，未怀孕供体成熟COCs中的凋亡细胞水平更高（P<0.01）。在IVM期间，怀孕和未怀孕供体的骆驼卵母细胞减数分裂分别在IVM的0 - 32小时和0 - 24小时伴随着周围卵丘细胞凋亡的急剧增加。与未怀孕供体的卵母细胞相比，怀孕骆驼的卵母细胞需要36小时的成熟时间才能达到>50%的中期2阶段水平，而未怀孕供体的卵母细胞32小时就足够了。未怀孕供体来源的COCs中凋亡的较早发生可能决定了卵母细胞通过减数分裂最后阶段的更快进程。
