The physiology of polyploid fish

这项研究的目的是以鱼类为实验模型，确定多倍体如何影响脊椎动物的生理过程。多倍体在它们的基因组中有比正常(二倍体)更多的两组染色体：三倍体有三个，四倍体有四个，等等。多倍体提供了冗余的基因，可以突变而不会造成死亡，在脊椎动物的进化中发挥了重要作用。多倍体的结果是增加了细胞核在总细胞体积中所占比例相对较大的细胞体积，导致细胞数量减少，单位体积的细胞和核表面积减少，细胞内扩散距离增加。这些变化可能会对个体动物施加生理限制，抵消多倍体的长期(进化)遗传利益。这项研究旨在确定这些制约因素的性质，从而帮助评估多倍体作为进化驱动力的更广泛意义。这项研究的重点是多倍体如何影响鱼类的红细胞动力学和有氧范围。这项研究将对鲑鱼和斑马鱼进行。鲑鱼相对较大，容易养殖，对水产养殖和渔业管理具有重要意义。斑马鱼是一种受欢迎的水族鱼，已成为研究脊椎动物发育的最重要模式物种之一。五名本科生和四名研究生将接受这笔助学金的培训。除了从这项研究中获得的基本知识外，它还将有利于加拿大的水产养殖和渔业管理，因为三倍体被视为创造不能繁殖的鱼类种群的宝贵工具。了解三倍体的局限性将导致它们畜牧业的改善，并将确保它们的福利得到适当考虑。

The objective of this research is to determine how polyploidy affects physiological processes in vertebrates, using fish as experimental models. Polyploids have more than the normal (diploid) two chromosome sets in their genomes: triploids have three, tetraploids have four, etc. Polyploidy has played an important role in vertebrate evolution by providing redundant genes that can mutate without causing lethality. A consequence of polyploidy is increased cell volume in cells for which the nucleus occupies a relatively large proportion of total cell volume, resulting in reduced cell numbers, reduced cellular and nuclear surface area per unit volume, and increased intracellular diffusion distances. These changes likely impose physiological constraints on individual animals that counterbalance the long-term (evolutionary) genetic benefits of polyploidy. This research aims to determine the nature of such constraints, thereby helping to assess the broader significance of polyploidy as a driver of evolution. The focus of this research is on how polyploidy affects erythrocyte dynamics and aerobic scope in fish. The research will be conducted with both salmonids - relatively large, easily cultured fish of importance for aquaculture and fisheries management - and zebrafish - a popular aquarium fish that has become one of the most important model species for research on vertebrate development. Five undergraduate and four graduate students will be trained with funding from this grant. In addition to the basic knowledge gained from this research, it will benefit aquaculture and fisheries management in Canada, as triploidy is seen as a valuable tool for creating reproductively sterile populations of fish. Understanding the limitations of triploids will lead to improvements in their husbandry and will ensure that their welfare is properly considered.