The gut to gills of ion regulation

我的研究计划的首要目标是了解鱼类和其他水生脊椎动物是如何调节它们的盐(离子)和pH水平的，这对生存至关重要。为了了解分子水平或离子转运蛋白的作用机制，我的研究将全动物方法与分子遗传学、生化和细胞技术相结合。开发抗体来探测离子转运蛋白的表达为我的研究提供了支柱，我计划通过结合新的基因编辑技术(CRISPR-Cas9‘Knokout’)来扩展这一研究，以了解更多关于潜在机制的信息。在接下来的五年里，我的研究将探索氢-钾ATPase(HKA)的功能作用，它也是导致胃酸的离子运输蛋白。HKA的胃酸作用在脊椎动物(从鲨鱼到人类)中高度保守，并提高了蛋白质和磷的消化效率，而蛋白质和磷是生长和骨骼发育所必需的。尽管胃很重要，但我们面临着胃丢失的悖论，在脊椎动物进化史上，这种悖论已经独立出现过多次。我们最近对已报告的17种鱼中的三类鱼进行了检查，结果表明，胃的丧失伴随着负责胃消化的基因的丢失。导致胃酸减少的原因有很多，但尚不清楚，但很可能与HKA在胃酸化中的作用有关。此外，HKA有多个变异(并列)，其表达部位在胃之外，涉及离子(钾)和pH调节。在鱼类中，鳃是离子和pH调节的重要器官。对体内钾的调节对于神经和肌肉的正常功能也是必不可少的，在这些地方，微小的变化可能会产生巨大的不利影响。拟议的研究计划旨在解决：(1)胃酸化的成本；(2)胃酸化丧失的潜在原因和(3)胃酸化丧失的后果；(4)胃基因丢失与胃的关系；以及(5)不同的HKA变体在不同动物群体的离子和pH调节中所起的作用。这些项目将建立在已建立的国际合作的基础上，并创造新的合作，改善加拿大的研究状况。此外，该计划还为提供高水平研究技能的年轻科学家提供了强有力的培训内容，这将促进他们融入加拿大的研究社区和行业。除了提高我们对基因丢失在进化中的作用的理解外，该计划还对加拿大的水产养殖业具有明显的实际意义。在加拿大，更好地了解胃在消化中的作用可以改进饲料配方，以提高生长和产量，同时减少浪费和污染。

The overarching goal of my research program is to understand how fishes and other aquatic vertebrates regulate their salt (ions) and pH levels, which are vital for survival. In order to understand the mechanisms at play down to the molecular level or the ion transport proteins, my research integrates whole-animal approaches with molecular-genetic, biochemical and cellular techniques. The development of antibodies to probe the expression of ion transport proteins provides the backbone of my research, which I plan to extend by incorporating novel gene editing techniques (CRISPR-cas9 `knockouts') to learn more about the underlying mechanisms. In the next five years, my research will explore the functional roles of the hydrogen-potassium ATPase (HKA), which is also the ion transport protein responsible for stomach acidification. Stomach acidification by HKA is highly conserved in vertebrates (sharks to humans) and increases the efficiency of protein and phosphorus digestion that are essential to growth and skeletal development. Despite the importance of the stomach, we are presented with the paradox of stomach loss, which has occurred independently multiple times in vertebrate evolutionary history. Our recent examination of three groups of fishes, out of 17 where stomach loss has been reported, indicates that loss of the stomach is accompanied by loss of the genes responsible for stomach digestion. The causes of stomach loss are many, and not well understood, but are likely related to the role of HKA in stomach acidification. In addition, the HKA has multiple variants (paralogues) with sites of expression outside the stomach that are involved in ion (potassium) and pH regulation. In fishes, the gills are an example of an important organ in ion and pH regulation. Regulation of body potassium is also essential for the proper functioning of nerves and muscles, where small changes can have dramatically adverse effects. The proposed research program aims to address: (1) the costs of stomach acidification; (2) the potential causes and (3) consequences of loss of stomach acidification; (4) the relationship between the loss of the stomach genes and the stomach; and (5) the roles that the different variants of HKA play in ion and pH regulation in different groups of animals. These projects will build upon established international collaborations and create new ones, improving Canada's research profile. In addition, the program has a strong training component for young scientists providing high-level research skills, which will facilitate their integration into Canada's research community and industries. In addition to improving our understanding of the role of gene loss in evolution, the program has obvious practical implications to Canada's aquaculture industry where a better understanding of the stomach's role in digestion can lead to improvements in feed formulations to increase growth and production, while reducing waste and pollution.