Wilsher Sandra, Allen W R
The Paul Mellon Laboratory of Equine Reproduction, Cheveley Park, Newmarket, Suffolk, UK.
Reproduction. 2009 Mar;137(3):583-93. doi: 10.1530/REP-08-0328. Epub 2008 Dec 12.
Eight day 10 horse embryos were transferred non-surgically to recipient mares that had ovulated 7 days after the donors. The embryonic vesicle was seen ultrasonographically in all eight recipients, and three out of eight (38%) of the vesicles developed an embryo proper with a beating heart. Conceptus expansion was initially slower than that in control mares but continued until day 22 (recipient day 15). Time of fixation of the vesicle was related to its diameter, rather than uterine stage. Although the embryo proper first appeared ultrasonographically on day 22, as normal, it grew more slowly and the allantois expanded more slowly than that in control mares with normal pregnancies. The development of endometrial cups and their secretion of equine chorionic gonadotropin in the two mares allowed to remain pregnant to >50 days occurred at a conceptus age approximately 7 days later than that in the control mares. The results demonstrated the uniqueness of the horse conceptus in being able to overcome a 7-day asynchrony with the uterus, and also highlighted the overriding influence of the uterine environment on conceptus development in the mare.
将8个妊娠第10天的马胚胎非手术移植到在供体排卵7天后排卵的受体母马体内。通过超声检查在所有8个受体中均可见胚泡，其中8个胚泡中有3个（38%）发育出带有跳动心脏的正常胚胎。孕体扩张最初比对照母马慢，但一直持续到第22天（受体第15天）。胚泡着床时间与其直径有关，而非与子宫阶段有关。尽管正常情况下超声首次在第22天观察到正常胚胎，但它生长较慢，尿囊扩张也比正常妊娠的对照母马慢。在两只妊娠超过50天的母马中，子宫内膜杯的发育及其马绒毛膜促性腺激素的分泌发生的孕体年龄比对照母马晚约7天。结果表明马孕体能够克服与子宫7天的不同步性，这一特性十分独特，同时也突出了子宫环境对母马孕体发育的首要影响。
