The physiology of polyploid fish

多倍体鱼的生理学

• 批准号: 46180-2011
• 负责人: Benfey, Tillmann
• 金额: $ 2.26万
• 依托单位: University of New Brunswick
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=593150
• 关键词: physiology; polyploid; fish

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 the cardio-respiratory system, by examining red blood cells (RBCs) directly, as well as the capillaries and gill lamellae (the sites of respiratory gas exchange, where RBCs travel through the narrowest passages) and the heart (which needs to provide sufficient pressure to drive blood through the circulatory system). A variety of techniques will be used, including light, electron and confocal microscopy as well as Doppler flow analysis, both in vivo and in vitro. 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 two 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.

本研究的目的是确定多倍体如何影响脊椎动物的生理过程，使用鱼类作为实验模型。多倍体在其基因组中比正常（二倍体）多两组染色体：三倍体有三组，四倍体有四组，等等。多倍性的结果是细胞中细胞体积增加，其中细胞核占据总细胞体积的相对大的比例，导致细胞数量减少，每单位体积的细胞和细胞核表面积减少，以及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，以抵消多倍体的长期（进化）遗传益处。这项研究旨在确定这些限制的性质，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心肺系统，通过直接检查红细胞（RBC），以及毛细血管和鳃板（呼吸气体交换的部位，RBC通过最后的通道）和心脏（需要提供足够的压力来驱动血液通过循环系统）。将使用各种技术，包括光，电子和共聚焦显微镜以及多普勒血流分析，在体内和体外。这项研究将对鲑鱼和斑马鱼进行，鲑鱼是一种相对较大、易于养殖的鱼类，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馆鱼类，已成为脊椎动物发育研究的最重要模式物种之一。五名本科生和两名研究生将利用这笔赠款接受培训。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生殖不育鱼类种群的宝贵工具。了解三倍体的局限性将导致其畜牧业的改善，并将确保其福利得到适当考虑。