The teleost taar family of olfactory receptors: From rapidly evolving receptor genes to ligand-induced behavior

摘要: Trace amine-associated receptors (TAARs) have recently been shown to function as olfactory in mammals. In this current study, the taar gene family has delineated jawless, cartilaginous, and bony fish (zero, 2, >100 genes, respectively). I conclude that genes are evolutionary much younger than related OR ORA/V1R receptor families, which present already lamprey, a jawless vertebrate. The 2 cartilaginous appear be ancestral for classes, each with mammalian (teleost) representatives. Unexpectedly, whole new clade, class III, of originated even later, within teleost lineage. Taar from all 3 classes expressed subsets zebrafish neurons, supporting their receptors. highly conserved TAAR1 (shark,mammalian, orthologs) is not epithelium may constitute sole remnant primordial, non family. Class III comprises three-fourths characterized by complete loss aminergic ligand-binding motif, stringently 25 other classes. Two independent intron gains represent extraordinary dynamics, considering virtual absence during vertebrate evolution. dN/dS analysis suggests both minimal global negative selection an unparalleled degree local positive another hallmark genes. accelerated evolution conceivably might mark birth Ligands only identified handful mammals insects, while single deorphanized, member OlfC family, OlfCa. Zebrafish TAAR classI good candidates having amines possible ligands, due presence ligand binding motifs. This study identifies diamines specific ligands receptor, DrTAAR13c. These activate sparse subset sensory indicated c-Fos expression epithelium. Diamines, putrescine cadaverine, foul-smelling aliphatic polycations occur naturally result bacterial decarboxylation amino acids lysine arginine, respectively. 15 concentration environment correlated putrefication. behavioral assay, exposed low show dramatic, quantifiable aversion, it shows attraction towards food stimulus no response water. spectrum TAAR13c closely parallels effectiveness these diamines. data consistent existence defined neuronal microcircuit elicits characteristic behavior upon activation novum sense smell.