Department of Obstetrics and Gynaecology, Education Program in Reproduction and Development, Monash University, Melbourne, Australia.
The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Australia.
Sci Rep. 2021 Mar 5;11(1):5344. doi: 10.1038/s41598-021-84361-z.
Egyptian spiny mice are the only known species to have human-like menstruation and a postpartum ovulation. Unfortunately, no endocrine or morphological evidence has been provided for a postpartum ovulation in spiny mice, and while later stages of pregnancy have been well studied, early events including embryo implantation and spiral artery remodelling have not been reported. This study compared the sex steroid endocrinology and reproductive tract morphology of dams at eight timepoints (n = 40) postpartum to determine the timing of ovulation and the timing and invasiveness of embryo implantation in A. cahirinus. Reproductive tracts were fixed and stained for histology and immunohistochemistry, and plasma was prepared for enzyme-linked immunosorbent assay. Ovarian histology and estradiol-17B concentrations indicate ovulation within 48 h of parturition and then immediate resumption of follicular growth. Uterine histology and immunohistochemistry revealed progressive epithelial repair, endometrial growth and spiral artery assembly and remodelling in dams postpartum. Blastocysts were seen in the uterine lumen at day 4-5 postpartum and embryos had implanted superficially with minimal stromal invasion by day 5-6. This study provides further evidence for the unique, humanesque reproductive biology of spiny mice and for a postpartum ovulation using endocrine and morphological changes observed during early pregnancy. Taken together, our data suggest that spiny mice may act as appropriate models of human pregnancy disorders such as implantation failure or pre-eclampsia.
埃及刺鼠是唯一已知具有类似人类月经和产后排卵的物种。不幸的是，刺鼠产后排卵并没有提供内分泌或形态学证据，虽然对妊娠后期进行了很好的研究，但早期事件，包括胚胎着床和螺旋动脉重塑，尚未报道。本研究比较了产后 8 个时间点（n=40）的母鼠的性激素内分泌和生殖道形态，以确定 A. cahirinus 的排卵时间以及胚胎着床的时间和侵袭性。生殖道进行固定和染色以进行组织学和免疫组织化学检查，并制备血浆以进行酶联免疫吸附测定。卵巢组织学和雌二醇-17B 浓度表明排卵发生在分娩后 48 小时内，然后立即恢复卵泡生长。子宫组织学和免疫组织化学显示产后母鼠的上皮修复、子宫内膜生长和螺旋动脉组装和重塑逐渐进行。产后第 4-5 天可见囊胚在子宫腔中，第 5-6 天胚胎已浅层着床，基质侵袭最小。本研究进一步证明了刺鼠独特的、类似人类的生殖生物学，以及通过观察早期妊娠期间的内分泌和形态变化来证明产后排卵。总之，我们的数据表明，刺鼠可能是人类妊娠疾病（如着床失败或子痫前期）的合适模型。
