Modification of the intracellular signaling machinery leading to the acquisition of sperm fertilizing ability

我的研究项目的主要目的是更好地了解精子获得与卵子相互作用和受精的能力的机制。在这个过程中，精子的细胞内生化机制会被改变。有几个信号级联反应是由女性生殖道的模糊因素、卵子本身或排卵过程中随卵释放的卵泡产物触发的。我们发现了一些精子细胞内蛋白，它们被怀疑是精子具有受精能力时激活的信号通路的一部分。然而，这些酶的伙伴还没有确定。因此，我们的目标之一是确定我们蛋白质的上游和下游的因素，以便更好地了解精子发生了什么，使它们能够受精。此外，精子/卵子的相互作用是高度特异的现象。除了极少数例外，来自一种动物物种的精子只能使同一物种的卵子受精。来自两个配子的蛋白质都参与了这个识别过程。我们鉴定并部分纯化了一种精子蛋白质，这种蛋白质被认为是导致精子与卵子结合的原因。由于这种蛋白质在精子经历附睾成熟时会发生改变，我们对确定这些修饰的性质非常感兴趣。此外，我们怀疑随着精子获得其受精能力，这种蛋白质也会受到影响。因此，确定这些修饰的性质并了解它们如何影响这种蛋白质调节精子和卵子之间相互作用的能力是很重要的。在自然条件下，受精发生在女性生殖道中，在输卵管中。精子在向卵子的内部转运过程中获得与卵子相互作用和受精的能力。我研究计划的一部分是确定子宫或输卵管如何使精子受精。它是通过精子和上皮细胞之间的直接细胞相互作用还是通过女性生殖道的分泌物？

The major objective of my research program is to better understand the mechanisms by which sperm acquire the ability to interact with and fertilize the egg.  Sperm intracellular biochemical machinery is modified during this process.  There are several signalling cascade that are triggered either by poorly defined factors from the female reproductive tract, by the egg itself, or by follicular products that are released with the egg during the ovulation process.  We identified sperm intracellular proteins that are suspected to be part of a signalling pathway activated as sperm become fertilization competent.  However, the partners of these enzymes have not been identified.  One of our goals is therefore to identify the factors upstream and downstream of our proteins in order to have a better idea of what is happening to sperm to make them competent at fertilizing.  Furthermore, sperm/egg interactions are highly specific phenomena.  With only rare exceptions, sperm from one animal specie can only fertilize an egg from the same specie.  Proteins from both gametes are involved in this recognition process.  We identified and partly purified one of the sperm proteins putatively responsible for the sperm binding to the egg.  As this protein is modified when sperm undergo epididymal maturation, we are greatly interested to identify the nature of these modifications.  In addition, we suspect that this protein is also affected as sperm acquires its fertilizing competence.  It is, therefore, important to determine the nature of these modifications and to understand how they affect the ability of this protein to mediate the interactions between sperm and egg.  Under natural conditions, fertilization occurs within the female genital tract, in the oviduct.  Therefore, sperm acquire its ability to interact with and fertilize the egg during its internal transit toward the egg.  A part of my research program is to determine how the uterus or oviducts render sperm fertilization competent.  Is it through direct cellular interactions between sperm and epithelial cells or through secretions from the female reproductive tract?