Massive expansion of bitter taste receptors in blind cavefish, Astyanax mexicanus.

We report no adaptation for four mudskipper species, which exhibit 3-4 bitter taste receptor genes, and thus a typical teleost repertoire, shaped by few gene losses and minor gene duplications from an ancestral repertoire of four genes. However, and in sharp contrast to all other teleost fish species analysed, blind cavefish possess over twenty intact bitter taste receptors plus several pseudogenes, rivalling the complexity of the human bitter taste receptor repertoire. The gene duplications giving rise to the current cavefish bitter taste receptor repertoire appear to have occurred well before the loss of vision, consistent with this increase in repertoire size constituting a preadaptive trait that conceivably could compensate to some extent for the lack of visual cues.
PMID: 30295711 [PubMed - as supplied by publisher]

Source: Chemical Senses - October 5, 2018 Category: Biochemistry Authors: Shiriagin V, Korsching SI Tags: Chem Senses Source Type: research