Genome Wide Identification, Phylogeny, and Expression of Aquaporin Genes in Common Carp (Cyprinus carpio)

PLoS One. 2016 Dec 9;11(12):e0166160. doi: 10.1371/journal.pone.0166160. eCollection 2016.

Abstract

Background: Aquaporins (Aqps) are integral membrane proteins that facilitate the transport of water and small solutes across cell membranes. Among vertebrate species, Aqps are highly conserved in both gene structure and amino acid sequence. These proteins are vital for maintaining water homeostasis in living organisms, especially for aquatic animals such as teleost fish. Studies on teleost Aqps are mainly limited to several model species with diploid genomes. Common carp, which has a tetraploidized genome, is one of the most common aquaculture species being adapted to a wide range of aquatic environments. The complete common carp genome has recently been released, providing us the possibility for gene evolution of aqp gene family after whole genome duplication.

Results: In this study, we identified a total of 37 aqp genes from common carp genome. Phylogenetic analysis revealed that most of aqps are highly conserved. Comparative analysis was performed across five typical vertebrate genomes. We found that almost all of the aqp genes in common carp were duplicated in the evolution of the gene family. We postulated that the expansion of the aqp gene family in common carp was the result of an additional whole genome duplication event and that the aqp gene family in other teleosts has been lost in their evolution history with the reason that the functions of genes are redundant and conservation. Expression patterns were assessed in various tissues, including brain, heart, spleen, liver, intestine, gill, muscle, and skin, which demonstrated the comprehensive expression profiles of aqp genes in the tetraploidized genome. Significant gene expression divergences have been observed, revealing substantial expression divergences or functional divergences in those duplicated aqp genes post the latest WGD event.

Conclusions: To some extent, the gene families are also considered as a unique source for evolutionary studies. Moreover, the whole set of common carp aqp gene family provides an essential genomic resource for future biochemical, toxicological, physiological, and evolutionary studies in common carp.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Aquaporins / genetics*
  • Biological Evolution
  • Carps / classification
  • Carps / genetics*
  • Conserved Sequence
  • Fish Proteins / genetics*
  • Gene Duplication
  • Gene Expression
  • Genome*
  • Organ Specificity
  • Phylogeny*
  • Protein Isoforms / genetics
  • Sequence Alignment
  • Sequence Analysis, DNA
  • Terminology as Topic
  • Tetraploidy*
  • Zebrafish / classification
  • Zebrafish / genetics

Substances

  • Aquaporins
  • Fish Proteins
  • Protein Isoforms

Grant support

This research was supported by grants from the National Natural Science Foundation of China (No. 31422057), the National High-Technology Research and Development Program of China (863 program; 2011AA100401), and the Special Scientific Research Funds for Central Non-profit Institutes of Chinese Academy of Fishery Sciences (2014A03YQ01 and 2016GH02). The authors would like to extend their sincere appreciation to the Deanship of Scientific Research at King Saud University for funding this research (No. RG 1435-012). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.