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

Abstract

BackgroundAquaporins (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.ResultsIn 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.ConclusionsTo 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.

Unravelling the Complex Duplication History of Deuterostome Glycerol Transporters

“…The above findings for Teleostei primarily addressed the glp repertoires of diploid species. For the teleost lineages that experienced R4, the data for allotetraploid cyprinids were fully consistent with the previous reports for the common carp ( Cyprinus carpio ) in which the glp copy number is double (13–14 paralogs) that of zebrafish (7 paralogs) [ 68 , 74 ]. In the present context, however, the aqp10 genes were renamed aqp10aa and -10bb in diploid cyprinids and aqp10aa1 , -10aa2 , -10bb1 and -10bb2 in allotetraploid cyprinids.…”

Hepatic Glycerol Metabolism-Related Genes in Carnivorous Rainbow Trout (Oncorhynchus mykiss): Insights Into Molecular Characteristics, Ontogenesis, and Nutritional Regulation

“…Many of the enzymes involved in these processes are regulated by nutritional hormones (insulin and glucagon) such as Gk (Westergaard et al, 1998), Aqp9 (Lebeck, 2014), Pgp (Mugabo et al, 2016), and cytosolic Gpd1 (Patsouris et al, 2016). On a molecular level, only one study has been published in fish species (common carp Cyprinus carpio), which characterized the glycerol transporter gene, i.e., the one coding for the AQP9 (Dong et al, 2016). Until now, to our knowledge, no data are available concerning the molecular regulation of glycerol metabolism by nutrition in fish species.…”

Polyploidization and pseudogenization in allotetraploid frog Xenopus laevis promote the evolution of aquaporin family in higher vertebrates

“…In vertebrates, the AQP family was highly diversified due to whole genome duplication [ 9 , 27 ]. While the total number of AQP genes in mammals is relatively small when compared with that in fish families.…”