Dipartimento di Biologia Strutturale e Funzionale, Università di Napoli "Federico II", Complesso Universitario di Monte S Angelo, Via Cinthia, 80126 Napoli, Italy.
Theriogenology. 2010 Apr 1;73(6):796-801. doi: 10.1016/j.theriogenology.2009.07.005. Epub 2009 Aug 13.
In mammals, sperm ascension within the female reproductive tract involves a transient adhesion to the caudal isthmus of the oviduct. Sperm adhesion to this specialized region, which is termed the "oviductal reservoir", extends the sperm fertile life span by delaying capacitation until, around ovulation, specific signals induce sperm release. In vivo and in vitro studies demonstrated that carbohydrates on the oviductal cell apical membranes and lectin-like molecules on the rostral sperm surface are involved in adhesion in a species-specific way. In this respect, the most intensely studied species are pigs and cattle. On the other hand, less is known about molecules involved in sperm release. Direct evidence that molecules present in the oviductal fluid trigger the release of sperm bound to in vitro cultured oviductal epithelium has been provided only in cattle. However, the identity of sperm and/or oviductal molecules that respond to these releasing signals is still unknown. The comprehension of molecular mechanisms underlying sperm-oviduct interaction may advance our understanding of the behavior of sperm within the female reproductive tract and provide new tools for sperm selection, extension of fertile life and modulation of capacitation in the field of reproductive biotechnologies. The aim of the present paper is to review the available knowledge on molecules involved in sperm selection, storage and release from the oviductal reservoir.
在哺乳动物中，精子在雌性生殖道内的上升过程涉及到与输卵管尾部峡部的短暂黏附。精子与这个特殊区域的黏附，即所谓的“输卵管储备库”，通过延迟顶体反应来延长精子的受精寿命，直到排卵前后，特定信号诱导精子释放。体内和体外研究表明，输卵管细胞顶膜上的碳水化合物和精子头表面上的类凝集素样分子以种属特异性的方式参与黏附。在这方面，研究最深入的物种是猪和牛。另一方面，关于参与精子释放的分子知之甚少。只有在牛中提供了直接证据，证明存在于输卵管液中的分子触发与体外培养的输卵管上皮结合的精子释放。然而，对这些释放信号做出反应的精子和/或输卵管分子的身份仍然未知。对精子-输卵管相互作用的分子机制的理解可能会促进我们对精子在雌性生殖道内行为的理解，并为生殖生物技术领域中的精子选择、受精寿命延长和顶体反应调节提供新的工具。本文的目的是综述与精子从输卵管储备库中选择、储存和释放有关的分子的现有知识。
