Functions of epidymosomes in sperm maturation

在哺乳动物的雄性生殖道中，精子必须沿附睾运输。附睾管是位于睾丸(输精管)和射精管(输精管)之间的一根长的单曲小管。附睾体的长度因物种不同而不同。据估计，公牛和种马的长度分别为5-7米和40米和80米。根据物种的不同，精子的附睾传递时间为3至12天。附睾上皮在管腔内分泌蛋白质，这些蛋白质与过渡精子相互作用。管腔内腔内分泌的蛋白质模式沿着附睾部变化，以顺序的方式修改成熟的雄配子。附睾发挥着不同的功能，这对男性生育是必不可少的。它参与精子的运输、浓缩、成熟和储存。附睾近端负责精子成熟，即获得受精能力，而附睾远端负责储存精子，确保射精时有足够数量的雄配子可用。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运输的过程中获得受精能力的。这个研究项目的目的是了解蛋白质是如何转移到精子中的，以及这些新分子的添加是如何调节精子功能的。这项研究计划可能导致体外策略，以提高具有高遗传值的公牛精子的受精率，而公牛的受精率较低。

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.