Universal scaling rules predict evolutionary patterns of myogenesis in species with indeterminate growth

Ian A Johnston, Bjarni K Kristjánsson, Charles G P Paxton, Vera L A Vieira, Daniel J Macqueen, Michael A Bell

Research output: Contribution to journalArticlepeer-review

Abstract

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 (FN(max)) 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 FN(max) 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.

Original languageEnglish
Pages (from-to)2255-61
Number of pages7
JournalProceedings of the Royal Society B-Biological Sciences
Volume279
Issue number1736
DOIs
Publication statusPublished - 7 Jan 2012

Keywords

  • Adaptation, Physiological/genetics
  • Animals
  • Biological Evolution
  • Body Size
  • Ecosystem
  • Gene Flow
  • Iceland
  • Muscle Development
  • Muscle Fibers, Skeletal/physiology
  • Smegmamorpha/physiology
  • Trout/physiology

Fingerprint Dive into the research topics of 'Universal scaling rules predict evolutionary patterns of myogenesis in species with indeterminate growth'. Together they form a unique fingerprint.

Cite this