Biodiv Sci ›› 2014, Vol. 22 ›› Issue (1): 80-87.DOI: 10.3724/SP.J.1003.2014.13237

Special Issue: 基因组和生物多样性

• Orginal Article • Previous Articles     Next Articles

Biodiversity and adaptive evolution of Antarctic notothenioid fishes

Qianghua Xu1,3,4, Zhichao Wu1,2, Liangbiao Chen1,2,*()   

  1. 1. College of Marine Sciences, College of Fisheries and Life Sciences, Shanghai Ocean University, Shanghai 201306
    2. Key Laboratory of Aquaculture Resources and Utilization, Ministry of Education, Shanghai 201306
    3. Key Laboratory of Sustainable Exploitation of Oceanic Fisheries Resources, Ministry of Education, Shanghai 201306
    4. National Distant-water Fisheries Engineering Research Center, Shanghai 201306
  • Received:2013-11-07 Accepted:2014-01-17 Online:2014-01-20 Published:2014-02-10
  • Contact: Chen Liangbiao

Abstract:

The sea surrounding the Antarctic continent is one of the coldest regions in the world. It provides an environmentally unique and isolated “hotbed” for evolution to take place. In the past 30 million years, species of Perciform suborder Notothenioidei evolved and diversified from a benthic and temperate-water ancestor, and now dominate the fish fauna of the coldest ocean. Because of their distribution across temperature zones both inside and outside the Antarctic Polar Front, notothenioid fishes are regarded as excellent model organisms for exploring mechanisms of adaptive evolution, particularly cold adaptation. We first summarize research progress on the biodiversity of Antarctic fish and then review current findings on the peculiar biological characteristics of Antarctic notothenioids that evolved in response to a freezing environment. Research has revealed that extensive gene duplication and transcriptomic changes occurred during the adaptive radiation of notothenioid fish. Examples of highly duplicated genes in the Antarctic lineages include genes encoding hepcidin, and zona pellucida proteins, in addition to various retrotransposable elements. A few genes from Antarctic notothenioid fishes have been used as transgenes and demonstrated to be effective in making transgenic plants cold-hardy. In the coming years, the genomes of some Antarctic notothenioid species will be fully sequenced and the adaptive functions of duplicated genes will be further elucidated. Such studies will deepen our understanding of how genomes evolve in freezing environments, and provide an improved knowledge of molecular mechanisms of cold adaptation.

Key words: the Southern Ocean, Antarctic notothenioid fishes, diversity, adaptive evolution