Evolutionary Genetics: Smells like a Pseudo-pseudogene Marcus C. Stensmyr  Current Biology  Volume 26, Issue 24, Pages R1294-R1296 (December 2016) DOI: 10.1016/j.cub.2016.11.006 Copyright © 2016 Elsevier Ltd Terms and Conditions

Figure 1 Drosophila sechellia and its favorite fruit. (A) Drosophila sechellia is endemic to the Seychelles archipelago and exclusively feeds on and breeds in toxic noni fruit. The odor of this foul-smelling fruit is mainly comprised of esters and acids, which are detected by members of the odorant receptor (OR) and ionotropic receptor (IR) family, respectively. (B) Ir75a in drosophilid flies detects acids. Prieto-Godino et al. [6] has now found that even though the Ir75a gene in D. sechellia carries a premature stop-codon, this locus still generates a functional full-length protein. This pseudo-pseudogene is fixed in the D. sechellia population and thanks to three amino acid shifts in the ligand-binding domain has acquired a novel function, detecting butyric acid, instead of acetic acid. Current Biology 2016 26, R1294-R1296DOI: (10.1016/j.cub.2016.11.006) Copyright © 2016 Elsevier Ltd Terms and Conditions