Coopersmith C, Erskine M S
Department of Biology, Boston University, MA 02215.
J Reprod Fertil. 1994 Nov;102(2):451-8. doi: 10.1530/jrf.0.1020451.
The effects of differential mating stimulation on fertility in rats were examined by mating pro-oestrous females for one ejaculatory series in tests in which they could or could not self-regulate, or pace, the timing of intromissions received by males. Females were autopsied on days 7, 14 or 21 after mating, or on the expected day of birth to confirm pregnancy, and the number of implantation sites or of viable fetuses or pups determined. Because of substantial behavioural variability within an ejaculatory series, data from paced and nonpaced females were divided according to whether they received a low (< or = 8) or high (> or = 9) number of intromissions. The incidence of pregnancy was significantly reduced among paced females receiving few intromissions relative to that of any other group. Histological examination of ovaries from females autopsied on day 7 after mating suggested that the reduced pregnancy rate among this paced, low intromission group resulted from a failure of activation of the corpora lutea, a possible consequence of the low number of intromissions received by these females. However, in paced, low intromission females that became pregnant, litter size was significantly greater than in nonpaced, low intromission females. These results suggest a compensatory effect of the temporal patterning of intromissive stimulation on fertility. This effect is not a consequence of differential mortality after implantation since there was no difference in litter size among females autopsied at any of the four times. The differences between paced and nonpaced females may be attributable to preimplantation effects such as differential release of ova or sperm transport.
通过让处于发情前期的雌性大鼠与雄性大鼠交配一个射精序列，来研究差异交配刺激对大鼠生育力的影响。在实验中，雌性大鼠能够或不能够自我调节或控制雄性大鼠插入时段的时间。在交配后第7天、14天或21天，或者在预期分娩日对雌性大鼠进行解剖以确认怀孕情况，并确定着床部位的数量或存活胎儿或幼崽的数量。由于射精序列内存在显著的行为变异性，根据接受低（≤8）或高（≥9）次数插入的情况，将有节奏和无节奏雌性大鼠的数据进行了划分。与其他任何组相比，接受少量插入的有节奏雌性大鼠的怀孕发生率显著降低。对交配后第7天解剖的雌性大鼠卵巢进行组织学检查表明，这个有节奏、低插入次数组的怀孕率降低是由于黄体激活失败，这可能是这些雌性大鼠接受插入次数少的结果。然而，在怀孕的有节奏、低插入次数雌性大鼠中，窝仔数显著多于无节奏、低插入次数的雌性大鼠。这些结果表明插入刺激的时间模式对生育力有补偿作用。这种效应不是着床后死亡率差异的结果，因为在四个时间点任何一个进行解剖的雌性大鼠窝仔数没有差异。有节奏和无节奏雌性大鼠之间的差异可能归因于着床前的影响，如卵子的差异释放或精子运输。
