Functions of epidymosomes in sperm maturation

在哺乳动物雄性生殖道中，精子必须沿着附睾运动。附睾是位于睾丸（输精管）和射精管（输精管）之间的长的单曲小管。附睾的长度因物种而异。 据估计，男子可达5-7米，公牛和种马分别长达40和80米。精子的附睾通过时间为3至12天，取决于物种。附睾上皮在管腔内分泌蛋白质，与过境精子相互作用。分泌在管腔内的蛋白质的模式沿着附睾变化，以连续的方式修饰成熟的雄性配子。附睾发挥着不同的功能，这些功能对男性生育力至关重要。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的成熟，即获得可交配性，而附睾的远端部分参与精子储存，确保射精时有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沿着这个器官转运的过程中获得其可繁殖性的。这项研究计划的目的是了解蛋白质是如何转移到精子中的，以及这些新分子的加入如何调节精子功能。这项研究计划可能会导致在体外策略，以提高精子的高遗传价值的公牛表现出低生育力。

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.