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。由于即使是小幅提高牛的繁殖率也大大提高了肉和奶的产量，因此提高繁殖效率的研究将极大地有利于加拿大的养牛业和经济，并对全球粮食生产产生积极影响。在这方面，公牛的受精率尤其重要，因为一头精英公牛的冷冻精液可能达到数百万剂，可以用于繁殖。因此，准确预测这些公牛的生育力至关重要。根据常规的精液评估程序，公牛传统上被归类为令人满意的繁殖者，它们的繁殖力各不相同。因此，鉴定公牛繁殖力的分子标记并评估这些生物标记物含量变异的遗传基础，将使动物育种者和遗传公司能够在公牛早期的遗传选择中包含这些信息。在这方面，我的研究计划的长期目标是阐明男性生育的调节。在过去的研究中(在NSERC DG的支持下)，我获得了新的知识，即钠，钾ATPase(NKA)参与了公牛睾丸和精子功能的调节，并建议将ATP1A4(NKA蛋白家族的成员之一，仅存在于睾丸和精子中)作为受精标记。这项建议的重点是了解ATP1A4调节公牛受精的分子机制。我们将确定这种蛋白在协调和支持精子发生的睾丸细胞(Sertoli细胞)的生长和分裂中的作用(目标1)。由于成年公牛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开发公牛管理策略，以增加支持细胞的数量和繁殖潜力。我们最近报道了ATP1A4与PLC相互作用？(一种对受精至关重要的蛋白质)在获能(雌性精子最终成熟，使其具有受精能力)期间。然而，这种相互作用的生理意义及其对获能和受精的影响仍不清楚，这将在本研究中进行调查(目标2)。这些结果将提高与基因测试相关的生殖技术的效率，并在公牛尽可能早的年龄选择公牛以销售其精液。我们报道了ATP1A4是在精子获能过程中合成的。在这项提案中，我们将研究潜在的分子机制(目标3)。这项研究产生的新知识将对男性生育领域产生很大影响。总体而言，这些研究将创造新的知识，并在跨学科层面上进行重要应用，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名暑期学生，为他们的多样化职业生涯做好准备。

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.