PUBLICATION

At the root of T2R gene evolution: Recognition profiles of coelacanth and zebrafish bitter receptors

Authors
Behrens, M., Di Pizio, A., Redel, U., Meyerhof, W., Korsching, S.I.
ID
ZDB-PUB-201229-7
Date
2020
Source
Genome biology and evolution   13(1): (Journal)
Registered Authors
Korsching, Sigrun
Keywords
Bitter taste receptor, bony fish, calcium mobilization assay
MeSH Terms
  • Animals
  • Binding Sites
  • Calcium
  • Evolution, Molecular*
  • Gene Expression
  • HEK293 Cells
  • Humans
  • Ligands
  • Models, Molecular
  • Phylogeny
  • Receptors, G-Protein-Coupled/chemistry
  • Receptors, G-Protein-Coupled/classification
  • Receptors, G-Protein-Coupled/genetics*
  • Species Specificity
  • Taste/genetics*
  • Zebrafish/genetics*
PubMed
33355666 Full text @ Genome Biol. Evol.
Abstract
The careful evaluation of food is important for survival throughout the animal kingdom, and specialized chemoreceptors have evolved to recognize nutrients, minerals, acids and many toxins. Vertebrate bitter taste, mediated by the taste receptor type 2 (T2R) family, warns against potentially toxic compounds. During evolution T2R receptors appear first in bony fish, but the functional properties of bony fish T2R receptors are mostly unknown. We performed a phylogenetic analysis showing the "living fossil" coelacanth (Latimeria chalumnae) and zebrafish (Danio rerio) to possess T2R repertoires typical for early-diverged species in the lobe-finned and the ray-finned clade, respectively. Receptors from these two species were selected for heterologous expression assays using a diverse panel of bitter substances. Remarkably, the ligand profile of the most basal coelacanth receptor, T2R01, is identical to that of its ortholog in zebrafish, consistent with functional conservation across >400 million years of separate evolution. The second coelacanth receptor deorphaned, T2R02, is activated by steroid hormones and bile acids, evolutionary old molecules that are potentially endogenously synthesized agonists for extraoral T2Rs. For zebrafish, we report the presence of both specialized and promiscuous T2R receptors. Moreover, we identified an antagonist for one of the zebrafish receptors suggesting that bitter antagonism contributed to shape this receptor family throughout evolution.
Genes / Markers
Figures
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Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping