Hunter R H F
Institute for Reproductive Medicine, Hannover Veterinary University, Bünteweg 15, D-30559 Hannover, Germany.
Zygote. 2011 Aug;19(3):265-9. doi: 10.1017/S0967199410000341. Epub 2010 Jul 21.
In endeavouring to understand the nature of sperm-oviduct interactions in mammals, attention was focused on experimental models in which fertilization can occur without a preliminary phase of sperm head binding to the isthmus epithelium. The ovarian endocrine milieu imposed on the oviduct tissues plays an important role in the binding phenomenon, although less so after the time of ovulation. Nonetheless, a sperm suspension introduced into the peritoneal cavity or surgical insemination directly into the oviduct ampulla before ovulation can result in fertilization, as can a surgical model in which the isthmus has been resected and the remaining portions of the duct reanastomosed. Mating or artificial insemination after ovulation in pigs permits rapid sperm transport to the site of fertilization, and the frequency of polyspermic penetration increases with the post-ovulatory age of eggs.Strategies underlying sperm binding were considered, especially in terms of preovulatory sperm storage and suppression of full membranous maturation. These, in turn, raised the problem of how sperm binding in vitro to oviduct cells from prepuberal animals or to cells harvested during the luteal phase of the estrous cycle, or to cells from the ampulla or even the tracheal epithelium, can act to regulate sperm storage and maturation with precision. In an evolutionary perspective, preovulatory binding of diverse populations of cells to the endosalpinx may have developed as a form of fine tuning to assist in sperm selection, to synchronize completion of capacitation with the events of ovulation, and to promote monospermic fertilization by a controlled release of competent gametes.
在努力理解哺乳动物精子与输卵管相互作用的本质时，注意力集中在那些无需精子头部先与峡部上皮结合就能发生受精的实验模型上。施加于输卵管组织的卵巢内分泌环境在这种结合现象中起着重要作用，尽管在排卵后作用较小。然而，在排卵前将精子悬液引入腹腔或直接手术输精到输卵管壶腹部可导致受精，切除峡部并将输卵管其余部分重新吻合的手术模型也能如此。猪在排卵后交配或人工授精可使精子快速运输到受精部位，多精入卵的频率随卵子排卵后的时间增加。人们考虑了精子结合的潜在机制，特别是关于排卵前精子储存和完全膜成熟抑制方面。反过来，这又引发了一个问题，即体外精子与青春期前动物的输卵管细胞、发情周期黄体期收获的细胞、壶腹部细胞甚至气管上皮细胞的结合，如何能精确地调节精子储存和成熟。从进化的角度来看，不同细胞群体在排卵前与输卵管内膜的结合可能已发展成为一种微调形式，以协助精子选择、使获能的完成与排卵事件同步，并通过可控释放有受精能力的配子来促进单精受精。
