Karim K B, Fazil M
Am J Anat. 1987 Apr;178(4):341-51. doi: 10.1002/aja.1001780406.
Rhinopoma hardwickei hardwickei has an annual reproductive cycle. Although many of the females become inseminated from the latter half of February until about the middle of April, ovulation has not been recorded until the 11th of March. A single follicle reached full development and released one ovum from either of the ovaries with nearly equal frequency, and a single conceptus was carried in the ipsilateral uterine cornu during each cycle. The embryo descended into the uterus as an early morula and attained the bilaminar blastocyst stage before undergoing implantation. As the morula advanced in age, the embryonic surface of the zona became progressively more basophilic. Hence in advanced morulae, the inner surface of the zona pellucida took a dark stain with hematoxylin and appeared like a distinct thin membrane, while the rest of the thickness of the zona was eosinophilic. Although progestational changes commenced in both uterine cornua, they became augmented in the uterine cornu on the side of ovulation and blastocyst attachment. After blastocyst attachment, the contralateral cornu reverted to an anestrus condition. The progestational changes became less conspicuous from the cranial to the caudal end of the uterus. Evidently, there was a linear gradient in the progestational response of the uterus with the cranial end being most responsive and the caudal end least responsive. The precise mechanism which brings this about is not known.
哈氏菊头蝠具有年度繁殖周期。尽管许多雌性从2月下旬到4月中旬左右受精，但直到3月11日才记录到排卵。单个卵泡发育成熟，并以几乎相同的频率从任一卵巢释放一个卵子，每个周期中单个孕体在同侧子宫角着床。胚胎以早期桑葚胚的形式降入子宫，并在着床前发育到双胚层胚泡阶段。随着桑葚胚年龄的增长，透明带的胚胎表面逐渐变得更加嗜碱性。因此，在晚期桑葚胚中，透明带的内表面用苏木精染成深色，看起来像一层明显的薄膜，而透明带其余部分的厚度则呈嗜酸性。尽管两个子宫角都开始出现孕激素变化，但在排卵和胚泡着床一侧的子宫角中变化更为明显。胚泡着床后，对侧子宫角恢复到静止期。从子宫的头端到尾端，孕激素变化变得不那么明显。显然，子宫的孕激素反应存在线性梯度，头端反应最强烈，尾端反应最不强烈。导致这种情况的确切机制尚不清楚。
