Besenfelder Urban
Institute of Animal Breeding and Genetics, University of Veterinary Medicine, Vienna, Austria.
Anim Reprod. 2025 Aug 4;22(3):e20250017. doi: 10.1590/1984-3143-AR2025-0017. eCollection 2025.
The collection of early embryonic stages from the donor animal and their in vitro development through to transfer back into a recipient animal has gained enormous importance both in understanding embryo physiology and in its application for breeding purposes. Whereas not so long ago the focus was on embryo retrieval after superovulation from the donor animal, oocyte collection by follicular puncture followed by in vitro production (IVP) is now the main source of bovine embryos. However, as recent years of intensive research have shown, it appears to be very difficult to reproduce the extreme complex in vivo processes under laboratory conditions. Consequently, the quality/developmental capacity of embryos available for cryopreservation/storage/transport and transfer still lags behind that of embryos derived directly from animals. Embryo collection in bovine MOET programs is limited to the success of the animal's hormone treatment, embryo collection itself, and transfer on Day 7. IVP largely bypasses these developmental steps in the animal and focuses primarily on the presence of healthy follicular waves. It uses follicular puncture (ovum pick-up: OPU) to obtain immature oocytes, which undergo a three-stage in vitro process to produce embryos that are transferred to the uterus on Day 7. However, it is now known that important processes take place in the oviduct that have a lasting effect on the further development of the embryo. In animals, however, the development of embryos in the oviduct has not yet received sufficient attention. This review will present some highlights of the use of early embryonic stages from the oviduct in different species, but the scientific work mentioned is also largely based on the recent presentation at the AETE 2023 conference in Heraklion, Greece.
从供体动物收集早期胚胎阶段，并使其在体外发育直至再移植回受体动物，这在理解胚胎生理学及其在育种目的中的应用方面都变得极为重要。就在不久前，重点还在于从供体动物超排后进行胚胎采集，而如今，通过卵泡穿刺采集卵母细胞并随后进行体外生产（IVP）已成为牛胚胎的主要来源。然而，近年来的深入研究表明，在实验室条件下重现体内极端复杂的过程似乎非常困难。因此，可用于冷冻保存/储存/运输和移植的胚胎的质量/发育能力仍落后于直接从动物体内获得的胚胎。在牛的MOET计划中，胚胎采集仅限于动物激素处理的成功、胚胎采集本身以及第7天的移植。IVP在很大程度上绕过了动物体内的这些发育步骤，主要关注健康卵泡波的存在。它利用卵泡穿刺（采卵：OPU）获取未成熟卵母细胞，这些卵母细胞经过一个三阶段的体外过程以产生胚胎，并在第7天移植到子宫。然而，现在已知在输卵管中会发生对胚胎进一步发育有持久影响的重要过程。然而，在动物中，输卵管内胚胎的发育尚未得到足够的关注。本综述将介绍在不同物种中使用来自输卵管的早期胚胎阶段的一些亮点，但所提及的科学工作也很大程度上基于近期在希腊伊拉克利翁举行的2023年AETE会议上的报告。
