vom Saal F S, Pryor S, Bronson F H
J Reprod Fertil. 1981 May;62(1):33-7. doi: 10.1530/jrf.0.0620033.
Female mice that had developed in utero between 2 male (2M females) or 2 female (0M females) fetuses were housed individually at 32 days of age in the presence of a male. The 0M females had a significantly shorter cycle. When the females were housed in groups of 5 in the presence of a male, cycle length in 0M females was significantly longer than that of 2M females for the first cycle recorded, but this relationship reversed completely by the third and fourth cycles. These results are compatible with a hypothesis that former intrauterine proximity to male fetuses affects the intrinsic timing of the oestrous cycle and the capacity to emit oestrus-suppressing cues and/or the sensitivity to such cues.
在子宫内由两只雄性胎儿（2M雌性）或两只雌性胎儿（0M雌性）发育而来的雌性小鼠，在32日龄时单独饲养，并与一只雄性小鼠放在一起。0M雌性小鼠的周期明显较短。当雌性小鼠以5只为一组饲养并与一只雄性小鼠放在一起时，在记录的第一个周期中，0M雌性小鼠的周期长度明显长于2M雌性小鼠，但到第三个和第四个周期时，这种关系完全逆转。这些结果与一种假设相符，即先前在子宫内与雄性胎儿的接近程度会影响发情周期的内在时间安排以及发出抑制发情信号的能力和/或对此类信号的敏感性。
