Computer-Aided Sperm Analysis (CASA) of sperm motility and hyperactivation

在男性生殖系统中，附睾是一个附着在睾丸上的分泌小管，精子在其中与细胞外因子相互作用以获得活力和受精能力。尽管这种睾丸后成熟过程对男性生殖功能的控制至关重要，但其细胞和分子机制尚不清楚。在此背景下，我的nserc资助的研究项目旨在破译控制附睾功能和精子成熟的基本细胞间通讯机制。特别是，我们正在探索细胞外通讯介质的作用，如初级纤毛（PC）和细胞外囊泡（EV）在生物活性分子从供体细胞转移到受体细胞中的作用。除此之外，我们揭示了男性生殖系统中存在来自CP的ev（未发表的数据），附睾体细胞之间存在旁分泌通信系统（Jerczynski等人，PLoSOne 2016，首席研究员，转基因小鼠模型），以及体细胞和精子之间存在旁分泌通信系统(Sharma等人，Science, 2016，合作者，小鼠和牛模型；Alves et al ., 2020, Frontiers in Cell and Developmental Biology，首席研究员)通过小非编码rna的囊泡转运。虽然EV和其他细胞外因子确保了精子分子模式的改变，但我们希望评估它们在获得精子活力方面的贡献，精子活力是维持男性受精能力的重要参数。

Within the male reproductive system, the epididymis is a secretory tubule attached to the testis in which spermatozoa will sequentially interact with extracellular factors to acquire their motility and fertilizing ability. Although this post-testicular maturation process is essential for the control of male reproductive functions, the cellular and molecular mechanisms involved remain obscure. In this context, my NSERC-funded research program aims to decipher the fundamental intercellular communication mechanisms that control epididymal functions and sperm maturation. In particular, we are exploring the role of mediators of extracellular communication such as the primary cilia (PC) and extracellular vesicles (EV) in the transfer of bioactive molecules from a donor cell to a recipient cell. Among other things, we unveiled the presence of EVs derived from CP in the male reproductive system (unpublished data) and the existence of a paracrine communication system between the somatic cells of the epididymis (Jerczynski et al. al, PLoSOne 2016, Principal investigator, transgenic mouse model) as well as between somatic cells and spermatozoa (Sharma et al, Science, 2016, Collaborator, murine and bovine models; Alves et al, 2020, Frontiers in Cell and Developmental Biology, Principal investigator) via the vesicular transport of small non-coding RNAs. Although EV and other extracellular factors ensure the change in the sperm molecular pattern, we wish to evaluate their contribution in the acquisition of sperm motility, an essential parameter for maintaining male fertilizing abilities. In this perspective, we wish to acquire state-of-the-art kinetic imaging equipment such as the Computer Assisted Sperm Analysis (CASA). This equipment is essential for the quantitative and standardized analysis of sperm factors such as progressive motility, morphology, concentration and the presence of DNA fragmentation. Hamilton Thorne Inc's IVOS II-CASA system is an example of a CASA system that is used by leading andrology laboratories around the world for its versatility since it can be used in fundamental studies on small rodents (e.g. transgenic mice or mice genetically invalidated for ciliary or vesicular components) and large mammals (e.g. bovines). Beyond improving our understanding of the cellular and molecular mechanisms that govern the control of the fertilizing power of mammals, the use of this cutting-edge equipment in the context of our work will open up new perspectives for the breeding industry where the increase in the inbreeding coefficient of animals affects reproductive performance.