Na+/K+-ATPase and regulation of testis and sperm function

在不久的将来，全球对粮食的需求将大幅增加。由于牛的繁殖率即使适度提高也会大大提高肉和奶的产量，因此提高繁殖效率的研究将大大有利于加拿大的养牛业和经济，对全球粮食生产产生积极影响。在这方面，公牛的生育能力是特别相关的，因为潜在的数百万冰冻精液剂量的精英公牛可以用于育种。因此，准确预测这些公牛的生育能力是至关重要的。根据常规精液评估程序，传统上被归类为令人满意的繁殖者的公牛的生育能力各不相同。因此，鉴定繁殖能力的分子标记和评估这些生物标记在公牛中含量变化的遗传基础，将使动物育种者和遗传公司能够在早期公牛的遗传选择中包含这些信息。在这方面，我的研究项目的长期目标是阐明男性生育能力的调节。在我过去的研究（由NSERC DG支持）中，我获得了关于钠钾atp酶（NKA）参与公牛睾丸和精子功能调节的新知识，并提出了ATP1A4（仅存在于睾丸和精子中的NKA蛋白家族成员）作为生育标志物。本研究的重点是了解ATP1A4调节公牛生育力的分子机制。我们将确定这种蛋白在协调和支持精子发生的睾丸细胞（支持细胞）的生长和分裂中的作用（目的1）。由于成年睾丸中支持细胞的数量是精液生产潜力的决定因素，我们的研究结果将有助于制定公牛管理策略，以增加支持细胞的数量和它们的生殖潜力。我们最近报道了ATP1A4与PLC ？（一种对受精至关重要的蛋白质）在获能过程中（精子在雌性体内的最终成熟，使其具有受精能力）。然而，这种相互作用的生理意义及其对获能和受精的影响尚不清楚，本研究将对此进行研究（目的2）。这些结果将提高生殖技术的效率，这些技术与基因检测有关，并在尽可能早的年龄选择公牛以销售其精液。我们报道了ATP1A4在获能过程中在精子中合成。在本提案中，我们将研究潜在的分子机制（目标3）。本研究产生的新知识将对男性生育领域产生重大影响。总的来说，这些研究将创造新的知识，在跨学科水平上具有重要的应用，对全球粮食生产产生重大影响。我建议培养3名博士生和5名暑期生，为他们从事不同的职业做好准备。

Global demand for food will increase substantially in the near future. Since even a modest increase in the reproductive rate in cattle substantially enhances meat and milk production, research to improve reproductive efficiency will substantially benefit the Canadian cattle industry and economy, with positive effects on global food production. In that regard, bull fertility is particularly relevant, as potentially millions of frozen semen doses from an elite bull can be used for breeding. Therefore, accurate prediction of fertility of these bulls is critical. Bulls traditionally classified as satisfactory breeders based on routine semen evaluation procedures vary in their fertility. Therefore, identification of molecular markers of fertility and evaluation of the genetic basis for variation in the content of these biomarkers among bulls will enable animal breeders and genetic companies to include this information in genetic selection of bulls at their early age. In that regard, long-term goal of my research program is elucidating regulation of male fertility. In my past research (supported by NSERC DG), I generated new knowledge that Sodium, Potassium ATPase (NKA) is involved in regulation of testis and sperm function in bulls, and proposed ATP1A4 (a member of NKA protein family exclusively present in the testis and sperm) as a fertility marker. This proposal is focused on understanding the molecular mechanisms by which ATP1A4 regulates bull fertility. We will determine the contribution of this protein in growth and division of testicular cells (Sertoli cells) that coordinate and support spermatogenesis (Objective 1). Since number of Sertoli cells in the adult testis is a determinant of semen production potential, results of our study will contribute to developing bull management strategies for increasing Sertoli cell number and their reproductive potential. We recently reported that ATP1A4 interacts with PLC ? (a protein critical for fertilization) during capacitation (final maturation of sperm in the female enabling fertilizing ability). However, physiological significance of this interaction and its consequences to capacitation and fertilization remains unknown, which will be investigated in this study (Objective 2). These results will improve efficiency of reproductive technologies relevant for genetic testing and selection of bulls at their earliest possible age for marketing their semen. We reported that ATP1A4 is synthesized in the sperm during capacitation. In this proposal, we will investigate the underlying molecular mechanisms (Objective 3). New knowledge generated in this study will have a high impact on the field of male fertility. Overall, these studies will create new knowledge, with important applications at an interdisciplinary level with high impact on global food production. I proposed to train 3 doctoral trainees and 5 summer students, preparing them for diverse careers.