Functions of epidymosomes in sperm maturation

在哺乳动物的雄性生殖道中，精子必须沿着附睾运输。附睾是位于睾丸（输精管）和射精管（输精管）之间的一个长而弯曲的小管。展开的附睾的长度因种而异。据估计，男子体长5-7米，公牛体长40米，种马体长80米。精子的附睾过境时间为3至12天，这取决于物种。附睾上皮在腔室内分泌蛋白质，与过境精子相互作用。卵泡腔室分泌的蛋白质沿附睾变化，以顺序的方式改变成熟的雄性配子。附睾有不同的功能，对男性的生育能力至关重要。它参与精子的运输、浓缩、成熟和储存。附睾的近端部分负责精子成熟，即获得受精能力，而附睾的远端部分则负责精子储存，以确保在射精时获得足够数量的雄性配子。多年来，我的实验室一直在研究附睾的功能，以了解精子是如何在这个器官的运输过程中获得受精能力的。这项研究计划的目的是了解蛋白质如何转移到精子中，以及这些新分子的加入如何调节精子的功能。这项研究计划可能会导致体外策略，以提高高遗传价值的公牛精子的生育能力，但目前的低生育能力。

In the mammalian male reproductive tract, the spermatozoa have to transit along the epididymis. The epididymis is a long, single convoluted tubule located between the testis (vas efferens) and the ejaculation duct (vas deferens). The length of the unravelled epididymis varies from one species to the other. It is estimated to be 5-7 meters in men and as long as 40 and 80 meters in bull and stallion respectively. The epididymal transit time for spermatozoa is of three to twelve days depending on the species. The epididymal epithelium secretes proteins within the intraluminal compartment that interact with the transiting spermatozoa. The pattern of proteins secreted in the intraluminal compartment varies along the epididymis, modifying the maturing male gamete in a sequential manner. The epididymis plays different functions which are essential for male fertility. It is involved in sperm transport, concentration, maturation, and storage. The proximal part of the epididymis is responsible for sperm maturation i.e. the acquisition of fertilizing ability whereas the distal portion of the epididymidis is involved in sperm storage ensuring that male gametes are available in sufficient number at ejaculation. Since many years my laboratory investigates the function of the epididymis to understand how spermatozoa acquire their fertilizing ability during its transit along this organ. The objective of this research program is to understand how proteins are transferred to spermatozoa and how the addition of these new molecules modulates sperm functions. This research program may leads to in vitro strategies to increase fertility of spermatozoa of high genetic values bulls presenting with low fertility.