Importance of intracellular signaling in the regulation of sperm fertilizing competence

精子是高度分化的细胞，它的唯一作用是使卵子受精，以产生一个新的个体。为了达到这一目的，精子由两个截然不同的部分组成：头部和鞭毛，前者含有一半的父系遗传物质，后者是将遗传物质与卵子接触所必需的活动器官。虽然精子在睾丸出口处结构完整，但在附睾运输过程中，精子细胞获得了移动和与排卵卵子相互作用的能力。然而，直到射精时，它们才与精囊和前列腺的分泌物混合在一起。这个过程被称为运动激活。一旦进入女性生殖道，精子就会与细胞和分泌物相互作用，并在一个称为获能的过程中完全具备受精能力，这与精子运动的过度激活有关，精子运动更加活跃，增加细胞的速度和强度，以促进精子通过与卵子相关的衣层，如积云，积云是一种高度粘稠的富含蛋白聚糖的液体，含有连接在一起的积云细胞，以及透明带。卵母细胞形成的相对较厚的细胞外基质。调节获能过程和精子/卵子相互作用的机制尚不完全清楚，尽管影响不同细胞内信号转导途径的药物调节环AMP-、Ca2+-、pH-和蛋白酪氨酸磷酸化介导的事件。我的研究项目致力于进一步研究精子受精能力获得过程中的精子细胞内生化事件，并更好地表征精子与卵子相互作用的介质，这些介质将导致受精和基因独特个体的早期发育。毫无疑问，这项研究计划将对濒危物种、依赖成功繁殖的农业（乳制品、肉类）以及最终对生活方式和环境对男性生育能力有强烈影响的人类遇到的生育问题产生影响。

Spermatozoa are highly differentiated cells which only role is to fertilize the egg in order to produce a new individual. To achieve its goal, spermatozoa are made of two distinct compartments linked together: the head which contains half of the paternal genetic content, and the flagellum, which is the mobility organ required to bring the genetic content in contact with the egg. Although structurally complete at the exit of the testis, sperm cells acquire the ability to move and to interact with the ovulated egg during the epididymal transit. However, they but remain in immotile until ejaculation, when they are mixed with the secretions from the seminal vesicles and the prostate. This process is called motility activation. Once in the female reproductive tract, sperm interacts with cells and secretion, and become fully fertilization competent in a process called capacitation and is associated with the hyperactivation of sperm motility, which is more vigorous, increasing cell velocity and strength to facilitate sperm passage through egg associated vestments such as the cumulus, a highly viscous proteoglycan-rich fluid containing cumulus cells linked together, and the zona pellucida, a relatively thick extracellular matrix produced by the growing oocyte. The mechanisms regulating the processes of capacitation and sperm/egg interactions are not fully understood although agents affecting different intracellular signal transduction pathways regulating cyclic AMP-, Ca2+-, pH-, and protein tyrosine phosphorylation-mediated events are involved. My research program is devoted to further investigate sperm intracellular biochemical events during the acquisition of sperm fertilizing ability and to better characterize the mediators involved in the sperm interactions with the egg that will result in fertilization and early development of a genetically unique individual. This research program will undoubtedly have impact on fertility problems encountered in endangered species, in agricultural industries (dairy, meat) that depend on successful reproduction and, ultimately in humans where lifestyle and environment have strong impacts on male fertility.