Transcriptome Analysis Reveals L-amino Acids as Olfactory Stimulant in the Large Yellow Croaker (Larimichthys crocea)

Fish perceived small molecules with high aqueous solubility by chemoreception. The chemical senses of fish can be divided into olfaction, gustation and less well defined sense which is represented by the general chemical senses and the existing chemosensory cells [1,2]. Fish olfactory sense can detect four main classes of chemicals (odorants) mainly; amino acids, gonadal steroids, bile acids and prostaglandins. Amino acid is a kind of compound that is highly effective chemosensory stimuli in fish. Behavioral evidence has shown that amino acids are detected by a variety of fish [3] and electrophysiological experiments have proven that amino acids are highly effective stimuli in both olfactory and gustatory systems [4]. Three types of olfactory related receptor have been reported in the olfactory epithelium of fish; they include; Olfactory receptors (OR), Vomeronasal Receptor (VR) and Trace-Amine Associated Receptors (TAAR) [5,6] OR genes are a type of G-protein coupled receptors and they are being expressed in the ciliated sensory neurons.