期刊
PROCEEDINGS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES
卷 279, 期 1736, 页码 2255-2261出版社
ROYAL SOC
DOI: 10.1098/rspb.2011.2536
关键词
parallel evolution; dwarfism; muscle fibres; threespine stickleback; Arctic charr; scaling laws
资金
- Natural Environment Research Council of the UK [NE/E015212/1]
- Marine Alliance for Science and Technology for Scotland (MASTS) pooling initiative
- Scottish Funding Council [HR09011]
- National Science Foundation of the USA [DEB-0211391, 0322818]
- Natural Environment Research Council [NE/E015212/1] Funding Source: researchfish
- Direct For Biological Sciences
- Division Of Environmental Biology [0919184] Funding Source: National Science Foundation
- Division Of Environmental Biology
- Direct For Biological Sciences [0322818] Funding Source: National Science Foundation
- NERC [NE/E015212/1] Funding Source: UKRI
Intraspecific phenotypic variation is ubiquitous and often associated with resource exploitation in emerging habitats. For example, reduced body size has evolved repeatedly in Arctic charr (Salvelinus alpinus L.) and threespine stickleback (Gasterosteus aculeatus L.) across post-glacial habitats of the Northern Hemisphere. Exploiting these models, we examined how body size and myogenesis evolve with respect to the 'optimum fibre size hypothesis', which predicts that selection acts to minimize energetic costs associated with ionic homeostasis by optimizing muscle fibre production during development. In eight dwarf Icelandic Arctic charr populations, the ultimate production of fast-twitch muscle fibres (FNmax) was only 39.5 and 15.5 per cent of that in large-bodied natural and aquaculture populations, respectively. Consequently, average fibre diameter (FD) scaled with a mass exponent of 0.19, paralleling the relaxation of diffusional constraints associated with mass-specific metabolic rate scaling. Similar reductions in FNmax were observed for stickleback, including a small-bodied Alaskan population derived from a larger-bodied oceanic stock over a decadal timescale. The results suggest that in species showing indeterminate growth, body size evolution is accompanied by strong selection for fibre size optimization, theoretically allowing resources saved from ionic homeostasis to be allocated to other traits affecting fitness, including reproduction. Gene flow between small-and large-bodied populations residing in sympatry may counteract the evolution of this trait.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据